The Dzonggyap Lukhang (rdzong rgyab klu khang; "Naga Temple Behind the Palace") was built by the Sixth Dalai Lama (1683-1706) in the late seventeenth century on a small island in the middle of a small lake behind the Potala (po ta la) Palace. The lake was created when earth from the area was removed during the expansion of the Potala. The temple was rebuilt by the Eighth Dalai Lama (1758-1804) as a three-story building with a maṇḍala layout, and it retains this design to the present. The Thirteenth Dalai Lama (1876-1933) also renovated the temple. The temple used to be a popular place to visit on the fifteenth day of the fourth Tibetan month. In 1984, the building was again renovated and the outer walls were reinforced with concrete.