The second largest volcanic caldera in the world. Sierra Negra volcano in Isabela Galapagos. You can see the rocks formed by lava flows and volcanic fumaroles. It is considered one of the best places for hiking in South America. The Sierra Negra volcano has a height of 1,124 msl / 3,687 feet. It is one of the most active volcano with an age of 535,000 years. Its last eruption was in June 2018.