How often do you get the chance to walk through a tunnel of lava? Created by the flowing and cooling process of liquid magma, the underground lava tubes of Santa Cruz are simply breathtaking. The most popular is the Tunnel of Love, so named for the heart-shaped hole in the ceiling. Cool down with a splash in the fresh waters of Puerto Ayora, snorkel at Tortuga Bay or the mangrove-lined Garrapatero Beach and get friendly with the giant natives at the El Chato Tortoise Reserve.