<human>:  When was the Potala Palace, Lhasa built?
<bot>: The Potala Palace was built in the 7th century. It was built by the Tibetan king Songtsen Gampo, who was a Buddhist ruler. The palace was the residence of the Dalai Lamas, the spiritual and political leaders of Tibet. The Potala Palace is a huge complex of buildings and courtyards. It has over 20,000 rooms and covers more than 6 square miles!