The Bartang valley is known throughout the Pamirs for sacred sites, musicians and perhaps one of the most amazing features in the region, Sarez Lake. The lake was formed as a result of a strong earthquake in 1911. The earthquake resulted in a gigantic rockslide down onto Usoy village blocking the river, thus forming the lake. The elevation of the lake is 3,265meters, the length of the lake itself is 162 km and the width varies from 1.44 to 3.3 km. A cult-defense complex, "Kala" (fortress), is preserved in the Bartang village of Basid. The complex sits high on the rock and includes a fire worship area with a well preserved altar and fortress. Not far from the fortress is an ancient burial place of "saks" that was discovered during the construction of the local school. There is a functional sacred site named "Mushkilkusho" in Bartang valley, which has a special meaning among local peoples' beliefs. Situated inside a rock alcove, people come to this place to pray. They believe that it reduces their pain and the difficulties they meet in everyday life activities.