Dome

Pathway between enclosure all on the right and the tower area, with pergola arching overhead; A single-gabled circular building, built on a single level of marble stone base. It is located south of the Hall of Prayer for Good Harvests and resembles it, but is smaller. It is surrounded by a smooth circular wall, the Echo Wall (3.7 m high, 193 m circumference), that can transmit sounds over large distances. Built in 1530 during the Ming Dynasty reign of Emperor Jiajing (Ming Shizong or Zhu Houcong); rebuilt in present form in 1752 by Emperor QianLong (Qing dynasty). The east and west annexes and the vault inside the Echo Wall compound were used to hold divine tablets of various gods worshipped at the Circular Mound Altar, spirit tablets of ancestors, and other ceremonial objects. Source: Wikipedia; http://en.wikipedia.org/wiki/Main_Page (accessed 6/3/2013)