Heaven and Hell, or Cennet and Cehennem, are two collapsed cave systems in the limestone hills above Narlıkuyu. Hell is the smaller, deeper chasm, best seen from above. Heaven is the one you descend into, down hundreds of steps into a green, echoing hollow.
At the bottom of Heaven are the ruins of a small Byzantine chapel and the sound of an underground stream. The combination of geology, mythology, and damp shade makes this the strongest single reason to stop in Narlıkuyu.