Key Monastery (Ki Gompa) is the largest monastery in Spiti and arguably its most photogenic: a white-and-ochre pile of prayer halls, sleeping quarters, and storage rooms stacked on a rock spur above the Spiti River, visible for kilometres in every direction. It was founded in the 11th century and belongs to the Gelugpa (Yellow Hat) school of Tibetan Buddhism, the same tradition as the Dalai Lama.
Inside, the walls carry centuries of thangka paintings and murals depicting Buddhas, deities, and fierce protectors. The inner sanctum has a large gilded statue of the Shakyamuni Buddha surrounded by butter lamps and offerings. A collection of old weapons hangs in the entrance hall — trophies and donations from various patrons over the centuries. The monks here are welcoming; if you arrive early or stay nearby, you may catch the morning prayer session, which begins around 6am and involves resonant horns, drums, and cymbals that carry impressively across the valley. Accommodation is available in the monastery guesthouse at very modest cost.