[citation needed] The entrance to the Yerpa Valley is about 16 kilometres (9.9 mi) northeast of Lhasa on the northern bank of the Kyichu.
From there, it is another 10 kilometres (6.2 mi) to the famous ancient meditation caves in the spectacular limestone cliffs of the Yerpa Valley (Tibetan: བྲག་ཡེར་པ་, Wylie: Brag Yer-pa).
There are a number of small temples shrines and hermitages and the cliffs contain some of the earliest known meditation sites in Tibet, some dating back to pre-Buddhist times.
[3] After Lhalung Pelgyi Dorje assassinated the anti-Buddhist Bon Emperor Langdarma in 842 CE he is said to have hidden himself in a cave and meditated for 22 years.
[3] Later histories record that both Songtsen Gampo and Trisong Detsen (756–797) founded temples at Yerpa, and Klu-mes Tshul-khrims did some refurbishing in the 11th century.
[14] Police came to Yerpa after the disturbances of October 1987 and pasted notices on the temple doors warning people against taking part in "counter-revolutionary activities".