Off the south coast of Mallorca, this verdant isle is one of the last unspoiled places in the Mediterranean—the largest of the 19 islands of the Cabrera Archipelago. To protect its dramatic landscape, varied wildlife, and lush vegetation, it was declared a national park in 1991. Cabrera has had its share of visitors throughout history, from the Romans to the Arabs. The only intact historical remains are those of a 14th-century castle overlooking the harbor. Tours are operated daily by the Marcabrera company. Boats depart from Colònia Sant Jordi port, 47 km (29 miles) southeast of Palma. Tours, with a stop to swim or snorkel in the mysterious Cueva Azul (Blue Cave), start from €55; two-and-a-half-hour excursions by speedboat, leaving three times a day between 1 and 5, are €70.