I'd love to know where this is; it looks like an old concrete structure built in the midst of a karst formation. Photo found at Uncertain Times, but the vias track back to a photoaggregator. No matches with TinEye reverse image search. Any ideas would be appreciated (it was readers here who helped me track down the identity of Armenia's Tatev monastery).
Addendum - Identity established thanks to Manpace: "It is in Sorrento, Italy. The city is built atop seaside cliffs, with ravines like the one pictured that haven't been modernized. The photo is taken from a busy city street right in the middle of town. That is a mill, and has been abandoned for a couple centuries I think."
More pix here. Thanks, Manpace.