The Punta Suárez coast is defined by mounds of lava rocks and boulders punctuated with basalt cliffs. Geologists consider Isla Española to be one of the oldest islands in the Galápagos. They believe it was formed by a shield volcano that erupted underwater about four million years ago. It was then uplifted from the sea by a shift in tectonic plates. In the center of the island is the remnant of a caldera. The crater only reaches an elevation of 675 feet. The rest of the island is flat thanks to millions of years of wind erosion.