Amarnath Linga

The Amarnath cave in Jammu/Kashmir, located at an altitude of around 4,000 m, contains a stalagmite that is worshiped as Shiva Linga. In the month of Shravana, July/August, water drips into the cave and creates a linga made of ice that grows and passes with the waxing and waning moon.

Read about Amarnath here