You will notice lots of lava rocks along the shore of Shipwreck Bay. They are from a shield volcano that formed the southern part of San Cristóbal. Several eruptions occurred from 2.4 million to 650,000 years ago. Inside of the dormant crater is Laguna El Junco, the biggest freshwater lake in the Galápagos. The surrounding highlands feature a thick forest, a rarity on the mostly arid Galápagos. The island’s north was also created by volcanic activity yet is comparatively young (within the last few centuries). All of these lava flows fused together to form San Cristóbal. The island’s peak elevation of 2,395 feet is a mountain named Cerro San Joaquín.
