The Grotta dello Smeraldo is a cave, partly inundated by the sea and located in Conca dei Marini, Italy, on the Amalfi Coast.
Wikipedia https://en.wikipedia.org/wiki/Grotta_dello_Smeraldo
Address Via Smeraldo, 84010, Italy
Coordinates 40°36'53.729" N 14°34'3.319" E
