Deep, dark and mysterious, Lake Vostok is one of the largest subglacial lakes in the world. Once a large surface lake in East Antarctica, Lake Vostok is now buried under more than 3.7 kilometers (2.4 miles) of ice near Russia's Vostok research station. Covered with ice for millennia, cut off from light and contact with the atmosphere, Lake Vostok is one of the most extreme environments on Earth. The lake has been ice-covered for at least 15 million years. Lake Vostok is one of the largest lakes on Earth in size and volume, rivaling Lake Ontario in North America. The lake itself is 230 km (143 miles) long, 50 km (31 miles) wide and as much as 800 meters (2,625 feet) deep. Lake Vostok sits near the South Pole in East Antarctica. The presence of a large buried lake was first suggested in the 1960s by a Russian geographer/pilot who noticed the large, smooth patch of ice above the lake from the air. Airborne radar experiments by British and Russian researchers in 1996 confirmed the discovery of the unusual lake. Lake Vostok harbors a unique ecosystem based on chemicals in rocks instead of sunlight, living in isolation for hundreds of thousands of years. The types of organisms the scientists found suggested they derived their energy from minerals present in the lake and sources from the underlying bedrock. Life in Lake Vostok doesn’t just exist — it thrives. Over 3500 different species have been identified, including a whole group of totally novel organisms. Lake Vostok is one of the easiest subglacial lakes to detect due to its size, yet most of its secrets remain.