The next point of interest would be a visit to Thien Tru temple (chua Ngoai - Outer Temple). The temple was built in the 18th century. Thien Tru means heavenly kitchen. This name was derived from the imagination of the locals in this region. Supposedly, the rock formations in this area look like chefs busily working in the kitchen. The name Thien Tru is also the name of a constellation - for the god of the kitchen. Thien Tru temple is famous for the Thuy Tien tower, a granite monolith. To the right of Thien Tru temple is Tien Son grotto. Tien son is famous for the five granite statues and the various formations on the walls of the cave. When struck, these formations sound like a Vietnamese percussion instrument called "Khanh", and some sound like bells.