The Isole Tremiti Archipelago is situated about 12 miles north of the Gargano promontory (Torre Mileto is the nearest point) and 22 miles far from the harbor of Termoli.
It is made up of three big islands - San Domino, San Nicola and Caprara - of an islet called Cretaccio and of a smaller island called Pianosa, situated about 11 miles northeast from the first three islands and more than 30 miles from Gargano's coast.