The amphitheater, located on the slope of the hill Gektepe, was built in the IV century BC. with Mavsola and accommodated about 13 thousand spectators. In 1973, after archaeological excavations were carried out on the territory of the amphitheater, it was turned into an open-air museum.
Most recently, Turkcell and Ericsson have completed a large joint project to restore this unique structure, launched in 2000 under the direction of the Museum of Underwater Archeology of Bodrum. The previous restoration works of 1976-1985 were stopped due to the termination of the project funding.
The entrance to the tunnel, which was discovered in the course of previous works, was the most visible sign for visitors to the restoration, but was not fully open and studied until now. It is assumed that this tunnel leads to an ancient tomb.