Tapkeshwar Temple in Dehradun, also known as Tapkeshwar Mahadev Temple, is one of the most famous temples dedicated to Lord Shiva. Situated by the forest side, the main shivalinga at the temple is inside a natural cave. It is believed that Dronacharya did penance for 12 years in a cave near Dehradun in Uttarakhand. The cave is named Drona Cave after his name. Water drops from the ceiling of the cave trickle down over the Shivalinga in a continuous downpour, making for an interesting spectacle.

Legend

 Dronacharya could not afford to buy cow or cow milk for his son. Young Aswathama was a clever child to know his parent’s problem and prayed to lord Shiva for milk. Happy with child Aswathama’s prayer, lord Shiva provided him with milk drops which dripped on the Shiva ling in Drona Cave – the cave where Dronacharya and his family resided. Thus Aswosthama’s hunger and desire was fulfilled. Tapak means to drip, thus the name Tapkeshwar meaning that drips. Several years later, Ashwathama, did penance in the cave standing on one foot. Shiva is believed to have appeared before him and blessed him with great skills in archery. The idols of Dronacharya and Aswathama can been found at the enterance and inside the cave respectively.

Tapkeshwar Mahadev temple is widely popular pilgrimage in Dehradun. The beautiful temple of lord Shiva established in between the two hills attracts hundreds of tourists from and around Dehradun every month. This is the auspicious place where thousands of people pay their visit to see the special marriage ceremony of Shiva and Parvati. The water that drops down vanishes underground and can be seen only few yards away in the form of a stream.

A large festival is held on Shivratri day around the Tapkeshwar Temple in Dehradun. People in large numbers participate in the fair organized on the occasion of Shivratri and pay their obeisance to the deity every year.

Source: http://www.uttarakhandguide.com/district-guide/dehradun/tapkeshwar-mahadev-temple/