Kotumsar Caves are situated at a distance of about 40 km (25 mi) from Jagdalpur. Kotumsar Caves are about 35 meters below ground level and around 1371 meters long.
Kotumsar Cave is a subterranean limestone cave located near the banks of Kanger River in the western portion of National Park. It was discovered by the local people around year 1900 and explored by a renowned Geographar Shri Sankar Tiwari in the year 1951 and it is one of the best known caves in Chhattisgarh as well as in India.
The floor of the cave consists of soil/clay, pebbles, rocks and water pools with several lateral and downward passages. Perpetual darkness and constant temperature (28 °C + 1 °C) prevails inside the cave. For entry into the cave, cement concrete steps, Steel steps and railings are available near the entrance side.
These caves have got the distinction of being India's first most biologically explored cave. As they are underground, there is pitch-darkness inside. It features stalactite and stalagmite formations. Entry to the caves is through the narrow stairs and visitors have to pass through tall, narrow chambers for gaining access to the main hall that features superb acoustics. The caves feature five chambers having several blind wells. Lots of tribal tales are also associated with it and are also known as Gupanpal or Kutamsar Caves. The stalactites found inside the cave have been an interesting research topic for scientists and even arouse the curiosity among the visitors.
Kotumsar cave harbours a variety of fauna like bats, frogs, snakes, crickets, spiders, fishes, millipedes etc. Fishes and frogs are found in the ditches of the cave where as bats, spiders, crickets are found on the ceilings and walls of the cave. Dr. Jayant Biswas has well documented the biology of the cave organisms living in Kotumsar Cave
There is lack of oxygen when going deep into the caves. In view of which, for safety reasons, entry beyond certain points has been restricted.
The cave is closed from 15 June to 31 October during rainy season. The cave needs removal of debris before tourist season.