Belum Caves is located at Belum Village in Kolimigundla Mandal of Kurnool district about 360km from Hyderabad.
Belum Caves is the largest tourist cave in Indian subcontinent and the longest caves in plains of Indian Subcontinent, known for its stalactite and stalagmite formations. Belum Caves have long passages, spacious chambers, fresh water galleries and siphons. It is a natural underground cave formed by the constant flow of underground water.
Belum caves was formed due to erosion in limestone deposite in the area by Chitravati River, millions of years ago. This limestone caves was formed due to action of carbonic acid — or weakly acidic groundwater formed due to reaction between limestone and water. The deepest point in the cave is called Pathalaganga (150 feet from entrance level) where a perennial stream is found. A new and second Indian cavernicolous species of the genus Andhracoides was discovered from Pataalaganga chamber of Belum caves.
Belum Caves has a length of 3229 meters, making it the second largest natural caves in Indian Subcontinent. Today, 3.5 km of the cave has been successfully explored, though only 1.5 km is open to tourists. There are 16 different pathways, including the main entrance and there are deposits of Quartz in the caves. The caves are formed in Black Limestone.
The entrance pit was originally smaller than what one sees today. It has been broadened as part of development of the caves to install the staircase to allow visitors to descend and ascend easily. To enter inside the cave one should be accompanied by a guide and freely wandering in the cave is strictly prohibited. There are passages in the cave where one will have to crawl to pass by. There are some streams inside the cave. There is a chamber inside the cave where a lot of stalactites and stalagmites can be seen. The chamber is called Kotilingalu and the entrance to chamber is called Simhadwaram.
Belum Caves are geologically and historically important caves. There are indications that Jains and Buddhists monks occupied these caves centuries ago. Many Buddhists relics were found inside the caves. These relics are now housed in Museum at Ananthapur. Archaeological survey of India (ASI) also found remnants of vessels, etc. of pre-Buddhist era and has dated the remnants of vessels found in the caves to 4500 BC. There is a giant Buddha Statue near a hillock near the Belum Caves. The area of cave known as "Meditation hall" was used by Buddhist Monks. There is a chamber inside the cave called Saptasvarala Guha or Musical chamber where the limestone formations make metallic sounds.