The Great Wall of China

An illustrative and detailed map showing the greater geographical extents and ground points of the Great Wall of China, including the Great Wall Traces, Forts, Watchtower and Beacons, identified through various times of the Chinese Dynasties, started from the Qin Dynasty (221-206 BC), continued through Han, Liao, and Jin Dynasties, and finally entering the Ming Dynasty (1368-1664 CE).


Data Source: The KMZ files of the Great Wall of China is freely available to download at the site researchgate.net.

The Great Wall of China

The Great Wall of China is the most extraordinary feature of engineering in history and one of the most iconic man-made structures on the planet. It is the ultimate wonder of the world. It took more time, more people, and more material to build this mega structure than any other man-made features on this planet. The world’s longest wall is the biggest and an awe-inspiring feat of ancient Chinese defensive architecture. The Chinese great wall winds its way across west to east breadths of China, generally built along the historical northern borders of China, scaling all kind of terrains: deserts, rocky mountain peaks, valleys and deep gorges, till it reaches the sea in the far east. Some sources claim that a trace of the Great Wall of China is visible from the space as well.

But why did the Chinese go to that staggering length to build it. Well, as I read somewhere, the wall was the result of immense blood, sweet and fear the ancient Chinese people faced. The ancient northern borders of China were battle grounds of frequent invasions from the fearsome horse-riding archers - the Xiongnu. This forced the Chinese emperors to adopt a radical strategy; they decided to build a wall - a linear complex fortress. It was built to keep out the raiding parties of nomadic tribes of the Eurasian Steppe, including the Mongols, Turic and Xiongnu, of modern-day Mongolia and Manchuria and to protect the Chinese states, empires, and the Han people from these invaders. With the wall height raising up to 20 feet, the wall distinctively changed the landscape across the territories, blocking strategic week points and passing through various terrains, and evolved over 400 years and 6000 miles.

The Great Wall of China is a series of fortifications made of stone, brick, tamped earth, wood, and other materials. Millions of the people were involved in construction of the Great Wall over various times of the Chinese Dynasties, started in the Qin Dynasty (221-206 BC), continued through Han, Liao, and Jin Dynasties, and finally took advanced shape during the Ming Dynasty (1368-1664 CE). The labour force used to build the Great Wall were not very skilled craftsmen or engineers, but were common workers, soldiers, forcibly recruited farmers, slaves, convicts and war prisoners. Even then the Great Wall of China carries a simple yet sophisticated and wonderful design; simple enough to be built quickly and with locally available materials and sophisticated enough that still stand upright after centuries.

How I created this map

The KML file that I downloaded from the above-mentioned source was suitable for opening in Google Earth Pro desktop application, but was not suitable for opening on top of online Google Map. So, I studied the content and structure of the KML, made some changes using normal code editors, like Notepad++, SciTE Text Editor, and made changes so that all layers open in Google Map. I have edited the KML files to remove the folder view and converted the data for normal layered view. And then I have added generalised lines to show the extents of the great walls. The KML file was containing various point locations of the of the great walls, like pillar or post locations, fort positions, location of beacons or watchtowers. I interpreted these point locations on top of satellite image in Google Map and tried to draw the traces of the great walls in various dynasties as shown in the map.

Seeing the vastness of the Great Walls of China, it is difficult to draw the exact extents of the walls with precise orientations and alignments. But I have tried to use my best judgment, with whatever time available, to compare the KML data with the impressions seen in the background Satellite image and decide on the positioning of the wall. Somewhere it could be correct, somewhere it might not be accurate. I leave it on the viewer to interpret accordingly. After all, this map created just to explain the extents of the Great Walls of China and to show why it is considered as a wonder of the world.

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Seven Sisters of the North-East India

An informative map showing the geographical positions of the seven north-eastern sister states of India. Click on the polygons to know details about that state in the Legend Box.

The North-East Region of India

In India, North-East is a cumulative synonym for the seven north-eastern states namely Arunachal Pradesh, Assam, Meghalaya, Manipur, Mizoram, Nagaland and Tripura. These states cover about 8% of India's total area. Although there is great ethnic and religious diversity within these seven states, they bear similarities in terms of the political, social and economic spheres. The land of North East India has the most eco-friendly destinations full of natural attractions, the great wildlife, adventure options, tribal attractions and much more for perfect unexplored holiday tours.

The Northeast region can be physiographically categorised into the Eastern Himalayas, Northeast Hills (Patkai-Naga Hills and Lushai Hills) and the Brahmaputra and the Barak Valley Plains. The region is covered by the mighty Brahmaputra-Barak river systems and their tributaries. Northeast India has a subtropical climate that is influenced by its relief and influences from the southwest and northeast monsoons. It is the rainiest region in the country, with many places receiving an average annual precipitation of 2,000 mm (79 in), which is mostly concentrated in summer during the monsoon season. Cherrapunji, located on the Meghalaya plateau is the rainiest place in the world with an annual precipitation of 11,418.7 mm (449.6 in).

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UNESCO World Heritage Sites

An informative map showing locations of the UNESCO World Heritage Sites on Google map, scattered across various countries worldwide. Click on the red circular dots on the map, representing UNESCO World Heritage Sites, to know more details.


Data Source: UNESCO World Heritage Sites: Official World Heritage List in other formats

UNESCO World Heritage Sites

A World Heritage Site is a landmark or area which is selected by the United Nations Educational, Scientific and Cultural Organization (UNESCO) as having cultural, historical, scientific or other form of significance, and is legally protected by international treaties. The sites are judged important to the collective interests of humanity.

There are various parameters that needs to be fulfilled for a site or place to be selected by UNESCO as World Heritage Site. It should have either historical importance or should represent scientific or cultural value of the civilization. Once a site is selected as World Heritage Site, it is the responsibility of the central government of the country in which the site is located to protect and preserve it for future. India is fortunate enough that it has many sites selected as UNESCO World Heritage Sites owning to its rich and diverse heritage covering scientific, cultural, historical significance. As of 2018, India has 36 heritage sites, the sixth most of any country (Wikipedia), representing magnificent specimens of architecture, unique traditions of culture and amazing natural objects.

UNESCO World Heritage Sites are generally the places of tourist attraction and attract people from all over the world to visit them. Hence, it would be helpful for people, mainly like tourists, to know about the location and surroundings of these places before planning a tour. The above map was created after grooming the freely available KML file from the above-mentioned data source.

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The Bermuda Triangle

An interesting illustrative map showing the geographical extents of the Bermuda Triangle in the Atlantic Ocean, along with the approximate locations of the unsolved incidents that have happened in the region.

The Bermuda Triangle

The Bermuda Triangle, also known as the Devil's Triangle, is a loosely-defined region in the western part of the North Atlantic Ocean, where a number of aircraft and ships are said to have disappeared under mysterious circumstances.

Located in the Atlantic Ocean, the Bermuda Triangle extents are defined between Bermuda Island, Puerto Rico Island and Miami Beach in Florida as shown in the above map. The Bermuda Triangle has long been believed to be the site where a number of mysterious plane and boat incidents have occurred. While it has become part of popular culture to link the Bermuda Triangle to paranormal activity, most investigations indicate bad weather and human error are the more likely culprits.

Research has suggested that many original reports of strange incidents in the Bermuda Triangle were exaggerated and that the actual number of incidents in the area is similar to that of other parts of the ocean. While its reputation may scare some people, the Bermuda Triangle is actually part of a regularly sailed shipping lane with cruise ships and other boats also frequently sailing through the area.

But nevertheless, whether Bermuda Triangle is a myth or an unsolved mystery, the following incidents, which I compiled from various sources in the internet, also illustrated in the above map, can't be denied to have all really happened at the region!

Deering Shipwreak: On January 31, 1921, Carroll A. Deering a coal cargo vessel was sighted run aground on Diamond Shoals, an area off the coast of Cape Hatteras, North Carolina, that has long been notorious as a common site of shipwrecks.

Flight 19 Disappearance: Flight 19 was the designation of a group of five Grumman TBM Avenger torpedo bombers that disappeared over the Bermuda Triangle on December 5, 1945 after losing contact during a United States Navy overwater navigation training flight from Naval Air Station Fort Lauderdale, Florida. The same night the incidents happened, two Martin Mariner planes were sent for search operation, but then one of them never returned. A passing by freighter ship SS Gaines Mill reported that they saw a huge explosion on the ocean at a distance, but nothing was found in that reported spot.

Star Tiger and Star Ariel Disappearance: G-AHNP Star Tiger disappeared on January 30, 1948, on a flight from Azores to Bermuda, and G-AGRE Star Ariel disappeared on January 17, 1949, on a flight from Bermuda to Kingston, Jamaica. Both were Avro Tudor IV passenger aircraft operated by British South American Airways. Both planes were operating at the very limits of their range and the slightest error or fault in the equipment could keep them from reaching the small island Bermuda Triangle.

Douglas DST airliner Disappearance: The disappearance of a Douglas DST airliner, registered NC16002, occurred on the night of 28 December 1948 near the end of a scheduled flight from San Juan, Puerto Rico to Miami, Florida.

KC-135 Stratotanker Collided: On August 28, 1963, a pair of US Air Force KC-135 Stratotanker aircraft collided and crashed into the Atlantic. The Bermuda Triangle version of this story specifies that they did collide and crash, but there were two distinct crash sites, separated by over 160 miles (260 km) of water.

Ellen Austin Encounter: One of the more fascinating oceanic tales is that of the strange encounter between the Ellen Austin and an abandoned vessel found adrift near the Bermuda Triangle. The Ellen Austin‘s captain sent two separate crews to bring the vessel to New York as a salvage prize, however both crews mysteriously vanished, and the derelict was lost forever.

USS Cyclops Missing: The incident resulting in the single largest loss of life in the history of the US Navy not related to combat occurred when the cargo collier Cyclops, carrying a full load of manganese ore and with one engine out of action, went missing without a trace with a crew of 309 sometime after March 4, 1918, after departing the island of Barbados.

Connemara IV Drifting: A pleasure yacht was found adrift in the Atlantic south of Bermuda on September 26, 1955. The crew of the yacht vanished while the yacht survived being at sea during three hurricanes. An investigation revealed that she had dragged her moorings and gone to sea.

Marine Sulphur Queen Disappearance: SS Marine Sulphur Queen, a T2 tanker converted to carry molten sulphur, noted for its disappearance in 1963 near the southern coast of Florida, taking the lives of 39 crew members on board. On February 2nd 1963, Marine Sulphur Queen started her ill fated voyage from Beaumont, Texas destined towards Norfolk when she was carrying over 15000 tons of molten sulphur.

USS Proteus Disappearance: The USS Proteus (AC-9) was a Navy collier that had been converted into a merchant ship. It was never heard from again after November 23, 1941, when it left from St. Thomas in the Virgin Islands, bound for an East Coast port in the United States. The approximately 540-foot-long (165 meters) ship was carrying 58 crew men and a cargo of Bauxite ore to be made into aluminum, appears lost somewhere in the Bermuda Triangle.

USS Nereus Disappearance: USS Nereus (AC-10) was one of four Proteus-class colliers built for the United States Navy before World War I. The craft was named after the mythological Greek sea God Nereus, meaning protector of sailors. The USS Nereus was lost at sea sometime after 10 December 1941, at it mad its way to Portland, Maine, from St. Thomas in the Virgin Islands. It disappeared with a crew of 61 along the same route as its sister-ship, the USS Proteus, had disappeared in the previous month.

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Petroleum Production Sites of the World

An illustrative map showing petroleum production sites and their respective generalized petroleum basins occurring globally. In the map, “Oil Production Site” means the oil drills from where petroleum is recovered from the earth surface. And “Oil Field Basin” means a system of source and reservoir rocks where petroleum was formed, migrated and trapped. Click on the Oil Production Sites (red circles) or the Oil Field Basins (orange polygons) to know details about them.


Map Source and Credits:

1. Oil Production Sites (Point data): Giant Oil and Gas Fields of the World (Compiled by M.K. Horn)
2. Generalised Oil Field Basins (Polygonals): Drawn by Vinod Rowmuria, author of this blog site, taking reference from petroleum geology literatures.

What is this Map about?

Today’s world economy is driven by crude oil and the petroleum industry. Petroleum is the main source of energy till date and it is essential to maintain the present industrial civilization. Many industries run on petroleum products. And therefore its availability is a critical concern for many nations worldwide. The world has seen many wars because of this black gold.

Have you wondered how and where on this earth petroleum is produced? Going back to some basic geology, petroleum is a naturally occurring hydrocarbon material that is believed to have formed from animal and vegetable debris buried in deep sedimentary rock beds for millions of years. The petroleum, being less dense than the surrounding water, was expelled from the source beds and migrated upward through porous rock such as sandstone and some limestone until it was finally blocked by nonporous rock such as shale or dense limestone. In this way, petroleum deposits came to be trapped by geologic features caused by the folding, faulting, and erosion of the Earth’s crust. See the image below to understand the five ways how petroleum reservoirs are formed in the earth crust.

Petroleum is recovered mostly through oil drilling in the earth crust. Although natural petroleum springs or seepages are also found but such occurrences are very rare. Oil drilling comes after the studies of structural geology at the reservoir scale, sedimentary basin analysis, reservoir characterization, mainly in terms of the porosity and permeability of geologic reservoir structures. It is refined and separated, most easily by industrial distillation, into a large number of consumer products, from gasoline (petrol) and kerosene to asphalt and chemical reagents used to make plastics and pharmaceuticals. Petroleum is used in manufacturing a wide variety of materials, and it is estimated that the world consumes about 90 million barrels each day.

USA has come up as a huge contributor to the total petroleum production in the world. Its contribution amounts to almost 25% of the total production of petroleum globally. Subsequent contributors in this line of huge petroleum producing countries are Saudi Arabia, Russia, China, United Arab Emirates, etc. A complete list of countries by its petroleum production can be found here.

Petroleum is a fossil fuels. It take millions of years to form and therefore it is also considered to be a non-renewable energy source. We should use petroleum products (oil and gas) judiciously and try to save them as far as possible. Five ways how Petroleum reservoirs are formed can be understood from the self-explanatory image below. In the above map the Oil Production Sites i.e., those red circles represent the locations on the earth's surface from where the Petroleum reservoirs are accessed through sub-surface drilling to collect the crude oil from the trap shown below.

Subsurface accumulations of Oil and Gas in Reservoir

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Europe Map during Nazi Domination

A illustrative map showing the face of Europe during the height of Nazi domination under Hitler’s rule between 1939 and 1945. This page and the map are intended not to praise the Nazi rule but only to show the geographic extents of the deadly regime in Europe for educational purpose only.




One of the darkest and deadliest phases in the World History is the domination of Hitler’s regime from 1920s to 1945, when it went on capturing most of the European countries, and wiping out less than half of the world Jewish population alone. The Nazi Germany power rose to its peak during World War II, which finally ended after Soviet Union regained its power, a retaliating fight against Nazis of 3-years, suicide of Hitler, and final surrendering of Nazis in front of the Red Army in Berlin. The total number of non-combatants (civilians who are not taking a direct part in war) deliberately killed by the Germans were about 11 million, a figure that rises to more than 12 million if foreseeable deaths from deportation, hunger, and sentences in concentration camps are included.

The Rise and Fall of the Nazi Germany

At the height of its domination, Hitler ruled Nazi Germany occupied most of the European countries at various times between 1939 and 1945. Hitler’s victory-journey started in March 1938 when the Nazis occupied Austria. Later the same year they marched into the Sudetenland, a part of Czechoslovakia, and in March 1939 the German army invaded the rest of Czechoslovakia. This brought over half a million Jews under German control

The German invasion of Western Poland in September 1939 led to the start of the World War-II. The German army continued invading and occupied many other European countries, including the Netherlands, Belgium, Luxembourg, France, Denmark, Yugoslavia, Greece, Norway and Western Poland. By this time many millions of Jews were living in territories under German control.

Control of Nazi occupied territories was very critical. The Nazis often left local governments in place, provided they were either sympathetic or could be easily manipulated (called puppet regimes). Each occupied nation was appointed a Gauleiter – a senior Nazi official who ruled in the manner of a governor. The level of control and force wielded in each occupied country was often based on Hitler’s personal perception of it. Economies in occupied countries were forced to assist the Nazi war effort, with cheap supplies and labour. There were also social restrictions, such as control of the press, obligatory identity cards, checkpoints and curfews.

The most brutal Nazi occupation was in Poland. In September 1939 the Polish state was divided in two, with the invading Germans occupying the western half and the Soviet Union’s Red Army occupying the east. By early 1941 most Polish Jews population had been forced out of their homes and herded into ghettos and slave labour.

By the summer of 1940, the Nazis controlled much of Western Europe, including eastern France, the Baltic States. This occupation would not change significantly until the D-Day landings and the Soviet Union’s counter attack of 1944. Riding on the victory-journey, the Nazis continued moving towards east and invaded Soviet Union. By early December, 1941, the German stood less than 30 km from the Kremlin, (Moscow center) and they were able to see some of Moscow’s buildings with binoculars. But after being mired in a war of attrition deep into the Soviet Union for nearly 3 years, the Nazi offensive was no longer sustainable. Under the leadership of the Soviet leader Stalin, the Red Army planned winter offensive to teach lessons to the Nazi Germans. When the invasion began in the summer of 1941, Hitler took it for granted that victory would be swift, not preparing a contingency plan for a prolonged battle in harsh, Russian winter conditions. By early 1944, the Germans could not sustain their siege on the USSR any longer, and were forced into an all-out retreat. Suffering from a high loss of life and lack of supplies (due to continued attacks on supply lines), the Nazi army was also severely weakened, making it ripe for pursuing Soviet forces

By April 1945 the Soviet forces fought their way into the center of Berlin. Unable to bear the humiliating defeat from the Soviet Red Army, followed by the news of execution of Mussolini, Hitler presumably decided to finish himself to avoid his capture. On 29 April 1945, in a small civil ceremony in the Führerbunker, Hitler married Eva Braun and then on the very next day, he committed suicide by taking cyanide and shooting himself. The Nazi German forces then surrendered in front of the Soviet forces in Berlin on 2 May 1945.

How the map was created

I analysed various historical maps in image formats showing Nazi domination in the internet and downloaded a few with reliable information. I used these as raster images for input in ArcGIS. I then tried to geo-reference these image maps on top of world countries layer in ArcGIS. Although the geo-referencing was not very precise as the countries dataset has a scale of 1:3 million, not matching with that of the image maps, but an approximate geo-referencing was achieved. Once the raster images are geo-referenced on top of the countries shapefile, I tried to draw the historical boundaries showing in the image maps in a trial and error basis. Once the boundaries are drawn, I ran a series of Geoprocessing tasks in ArcGIS to clean and carve out the final maps from downloaded countries dataset. Sometimes the last two steps needed repetition in sequence back and forth to get the desired outcome. The final carved-out maps were in the form of shapefiles, with names and attributions as per the image maps. I then converted these shapefiles into Google’s KML format to overlay on top of Google map as shown in the above map.

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