The island of San Nicola, in the Tremiti archipelago, is home to Abbazia di Santa Maria a Mare. Founded in the 8C, it amassed riches, was coveted and then closed in 1782, before being transformed into a prison. Now restored, it boasts a superb Dalmatian Venetian-influenced portal, behind which treasures are hidden, including a mosaic pavement (11C-12C) and a wooden Byzantine cross. The walk to the cemetery (40min there and back) is very pleasant.