The underground tombs, many of which date back to the 3rd century BC, are carved out of solid rock, and are thought to have been the burial sites of aristocrats and high officials up to the third century.
The burial niches were looted of all artifacts long ago, but a powerful sense of stillness and mystery remains.
Some tombs are reached via stairs that lead into sunken rectangular courts surrounded by Doric columns carved from the rock. Originally the tombs were covered with stucco and the walls were decorated with frescoes.