Seamounts generally form when volcanic mountains rise up from the seafloor ... bouncing off the sub in every direction. A black-and-white manta ray flexes its wings and soars past for a look.

And yet few international travelers make the journey to, much less know anything about, Turkey’s Black Sea ... by rising mountains. On the shore, the twin-minareted white Uzungöl mosque appears ...

With a richly diverse natural landscape—from the vertiginous mountain peaks of the Caucasus to the balmy rainforests of the Black Sea-fronted Adjara region—the country of Georgia offers ...