The Letoon theatre dates to the 2nd century BC. Seating is still intact, but the theatre building has disappeared. It has 36 rows of seats, the cavea is divided into 11 sections. There is a horizontal footpath (diazoma). Author John Freely considers to be the most beautiful in Turkey. There are two tunnels at the diazoma level, one on the east, one on the north side. It is possible the sacred city was entered through one tunnel and left through the other.

Near the outside of the north tunnel there is a sacophagus with a person laid out during a funeral ceremony.