From Chusi Nunnery it’s a tough 1½-hour climb up to the Drak Yangdzong caves. Access to the upper caves is via a 10m ladder secured with strips of yak hide. Note that the caves are very narrow and slippery in places and are absolutely no place for those with claustrophobia, vertigo or a tendency to eat too many doughnuts. The spiritual and physical heart of the complex is a tiny Guru Rinpoche cave. It's great fun – or terrifying, depending on how you feel about caving.
The large cave below the main entrance has a chapel with an interesting side mural of Mindroling Monastery and a couple of resident nuns, who will act as your guide through the caves.
Back into the daylight (and after a quick round of butter tea) pilgrims continue to a side cave, which is smaller but leads down to a subterranean pool (the spirit lake of a dakini). A trail continues for 10 minutes to the ruins of a monastery on a spur.