At an elevation of 4,166 metres Key or Ki is the biggest monastery in Spiti valley with over 100 monks. It belongs to the Gelug sect of Buddhism. This monastery, founded by Dromtön in the 11th century, witnessed many atrocities. It was first destroyed in the 14th century, when Sakya sect rose in power, then by the Mongols in the 17th century, it was again damaged in the war between Ladakh and Kullu and then by a fire in 1840 and in 1975, a massive earthquake further damaged it.
It has three floors and accommodates around 250 monks in the winters.