Tagus Cove on Isabela has historically provided shelter for wayfarers and was one of the places Charles Darwin visited in 1835. A strenuous hike up the side of a volcanic tuff cone brings us to a wondrous view of Darwin’s Lake, where debate still rages as to the origin of the water (ask your Naturalist). Along the way, finches flit among the trees and the island’s craggy geologic features come into view. A stunning overlook to the other side of the island ends the trail. In addition, experienced snorkelers are availed a deep-water snorkel here and if conditions cooperate, it can be spectacular, filled with sea turtles, fish, penguins, cormorants and the possibility of seeing marine iguanas feeding underwater on algae.