AM: Today we will visit some of Isabela Island’s best attractions: the Sierra Negra and Chico volcanos. Sierra Negra is one of the most active volcanoes of the archipelago, and its crater – with a diameter of 10 kms – is considered the second largest in the world. “Volcan Chico” is also an active volcano, and sulfur vents can be seen spewing from it. This 6-hour walking tour will allow you to appreciate all the splendor of these amazing volcanoes. For those who do not wish to go on the volcano hike, an alternative activity is a visit to Los Tuneles. A 30 to 40 minute ride on a small speedboat will take you to this unique place where cooled lava flows have been impacted for ages by the ocean’s waves. This visitors’ site is a marine paradise for Whitetip reef sharks, Galapagos green sea turtles, Galapagos sea lions, manta rays, Parrot fish, Yellow-tail surgeon fish and many other aquatic species.