Rock-Tomb of a Pontic king (Amasya, Turkey)

Those royal tombs date from about 300 BC to 200 BC. They are carved in a vertical cliff above the city of Amasya, which used to be the capital of the Kingdom of Pontos.

The man in the photo gives a sense of scale. The tomb itself (with a window which is in fact the tomb door) is like a small monolithic structure completely separated from the mountain, i.e. they have carved a 2-3 meter space around the entire tomb, including in the back (which you cannot see here). So it is possible to go into the passage on the right side (near the man on the photo), walk around the tomb, and exit by the left side.

For more information about those rock-cut tombs, read en.wikipedia.org/wiki/Tombs_of_the_kings_of_Pontus.