Deep within the Earth, on the Philippine island of Palawan, flows the Puerto Princesa underground river. This stunning natural wonder — named so by UNESCO on its list of “New Seven Wonders of Nature”— flows through a gigantic cave that runs under Mount Saint Paul and is tens of miles long. Here, La Venta, the Italian world exploration group, takes the reader to this site of mythical proportions in stunning photographs, with this follow-up to their retrospective volume Into the Heart of the World (also from Skira).