Dungeshwari Cave Temples, also known as Mahakala caves, is situated 12 km north-east of Bodhgaya, in Gaya district Bihar. Gautama Siddhartha is believed to have piously meditated at this place for six years before he went to Bodhgaya for the final realization. Two small shrines are built to commemorate this phase of Buddha. A golden emaciated Buddha sculpture memorising the rigid penance is enshrined in one of the cave temples and a large (about 6’ tall) Buddha’s statue in the other. A Hindu goddess deity Dungeshwari is also placed inside the cave temple.

Dungeshwari cave temples are also popular as Sujata Sthan to local people. It is believed that when Buddha was doing his self-mortification, he became frail, feeble and starved. When he rested under a Banayan tree, a village woman named Sujata offered him food. Buddha accepted her offerings and consumed the food; his explicit approval presented him with a divine truth that neither extreme self indulgence nor self-abasement is the right way to attain enlightenment. Buddha attained the knowledge that following the middle path will lead to attaining the supreme nirvana. Sujata Sthan or Dungeshwari Temple stands as a symbol commemorating this event.

Source:

http://www.bihartourism.gov.in/districts/Gaya/dungeshwari.html

http://indianstemples.blogspot.in/2013/07/dungeshwari-cavemahakala-caves-temple.html