Puerto Princesa, Philippines

This independent city occupies the mid-section of Palawan island in the southern Philippines. It is a center for eco-tourism in the archipelago, with notable coral reefs offshore including one, Tubbataha Reef, designated as a UNESCO World Heritage Site. One of the most famous of its sites is the Puerto Princesa Subterranean River, a national park and the longest navigable underground river in the world. A boat ride into the karst limestone passages, lined with dramatic stalagmites and stalactites, is a must when visiting the island. The river was inscribed as a World Heritage Site by UNESCO in 1999 and recently was voted one of the New Seven Wonders of Nature.