Palha Lu-puk (next to Drubthub Nunnery) is an atmospheric cave temple said to have been the 7th-century meditational retreat of King Songtsen Gampo. The main attraction of the cave is its relief rock carvings, some of which are more than a thousand years old, making them the oldest religious images in Lhasa.
Altogether there are more than 70 carvings of bodhisattvas here; the oldest images are generally the ones lowest on the cave walls. Songtsen Gampo is depicted on the western (back) side. The yellow building above the Palha Lu-puk is a chapel that gives access to the less interesting meditation cave (drub-puk) of King Songtsen Gampo’s Chinese wife, Princess Wencheng.