Isla de Barú is one of Las Islas del Rosario, a national park popular with tourists and famous for its coral reefs, crystalline waters, and beautiful beaches. The islands are about 45km (28 miles) from the city and can only be reached by boat. You can arrange a trip to Las Islas del Rosario through your hotel or by heading to the Muelle Turístico, where you can buy tickets directly. Another option is to go through Tesoro Tours, Carrera 3 no. 6-153 (tel. 5/665-4713; www.tesorotours.com). Your hotel will also be able to arrange tours directly. Boat trips generally cost between COL$35,000 and COL$60,000, though you will also have to pay a national park tax of COL$9,400. Most tours stop on Isla de Barú for a typical Cartagena-Caribbean lunch, complete with coconut rice, fried plantains, and a whole fish (eyes and all). You can also skip the larger tour and go straight to Isla de Barú if you wish, where you can go swimming, sunbathe, or explore the island. Beware that beach vendors here are persistent, and the best way to be left alone is to get in the water as fast as possible.