The fortress of Por-Bazhyn is located on Lake Tere-Khol in Tuva and is a mysterious ancient structure known to geographers since the 17th century. Research has shown that the fortress was built by the Uyghur khan Bayan-Chorom in the 8th century. Archaeological excavations have revealed remnants of massive walls and palace buildings adorned with ornaments. The purpose of the fortress remains unclear, ranging from a summer residence to a defensive structure. Legends and recent research add to the mystery of this unique monument.

Legend has it that the fortress of Por-Bazhyn was built as a temple for worshipping the sun deity. Ancient Uyghurs believed that the sun deity dwelled in this place and constructed the fortress for conducting rituals and ceremonies associated with the sun. This explains the orientation of the structure and the presence of special ritual chambers inside the fortress.