Ages ago, a few volcanoes got together and decided to form an island. Gorgeous San Cristobal is a jewel of the Galapagos, where plump sea lions sun themselves on coral beaches and hermit crabs scuttle along peaceful lagoons. Snorkel or dive at Kicker Rock to explore the intricate remains of a lava cone, spot beautiful wildlife along the walking trails to aptly-named Frigatebird Hill, or frolic—slowly—with the legendarily large tortoises at the Galapaguera de Cerro Colorado nature preserve.