Puerto Princesa Underground River (In Philippines)

Located on the northern coast of the island of Palawa, Puerto Princesa is a nature lover’s paradise. Home to unspoiled landscapes rich in wildlife, this lovely town also lays claim to one of the world’s most unique natural phenomena, an underground river known as the Puerto Princesa Subterranean River. Protected within a national park, this natural wonder is the world’s longest navigable underground river. Guided paddle boat tours show intriguing rock formations and fluttering bats.