1. Son Bhandar caves

Located in Rajgir, Bihar, on the foothills of the Vaibhar hills, the Son Bhandar caves are two artificial structures from the 3rd or 4th century BC. Son Bhandar translates to ‘store of gold’.
According to legend, there is a secret treasure inside the caves. On one particular wall of the cave, there is a door that will open when the “right password” is uttered. The inscriptions, which are said to hold a clue to the gold, have not been deciphered by anyone so far.
The caves are said to be from the Mauryan empire and have a connection with Buddhism.

2. Edakkal caves

This located in Wayanad, Kerala, the Edakkal caves have unique carvings that are said to be thousands of years old. these caves are double-chambered and naturally formed. They are in Ambukuthi Mountain. More than 1,300 meters above sea level,
The carvings are set to date back to 6000 BC, during the neolithic stone age. It was discovered by British police officer Fred Fawcett.

3. Borra Caves

One of the largest caves in India, these limestone caves are in Vishakapatnam, Andhra Pradesh. They are home to million-year-old stalactite and stalagmite formations and are at an elevation of 1400 meters above sea level.
They were formed because of the flow of river Gosthani on the limestone deposits.
Legend says that a cowherd discovered the caves while looking for his cow, and he found a shiv ling (symbol of Lord Shiva) inside.

4. Undavalli Caves

Located in Vijayawada, Andhra Pradesh, these rock-cut caves are an example of Gupta architecture. Carved out of sandstone, they give us a glimpse into ancient religious practices.
There is a huge Lord Vishnu monolith in the reclining posture in one of the caves.