Volcán Darwin, named after the renowned naturalist, contains a symmetrical 5-km-wide, 200-m-deep summit caldera whose floor is nearly covered by youthful lava flows. A broad terrace occupies the SW part of the caldera. Fresh-looking, unvegetated lava flows descend all flanks and reach both the eastern and western coasts. The most recent summit activity produced several small lava flows from vents on the east caldera floor and NE and SE caldera rims. Radial fissures descend the flanks, and one reaches beyond its base to the the SW coast and cuts Tagus tuff cone. The sheltered anchorage of Tagus Cove breaches the southern side of the cone and was visited by Darwin and other noted visitors. This prominent tuff cone and its neighbor Beagle (also breached to the south) are located on the SW-flank coastline and were a prominent part of Darwin's geological studies in the Galápagos Islands.