One of the most holy sites in Tibet, the Tsuklakkhang (gtsug lag khang) is the heart of Lhasa, surrounded by the Barkor (bar skor) circumambulation route. The temple is also called the Jokhang (jo khang) because in its central wooden structure it houses the Jowo (jo bo), a statue of the young Buddha said to have been brought to Tibet by Wencheng, the Chinese wife of the Tibetan emperor Songtsen Gampo (srong btsan sgam po). The temple was originally built around 640 CE to house the buddha image brought by Songtsen Gampo's Nepalese wife, Bhṛkutī, but this statue was later switched with that of Wencheng. The temple complex has gradually expanded over the centuries. It remains today one of the most popular pilgrimage sites in Tibet.