Santiago Island (Isla Santiago), also known as James Island or Isla San Salvador, actually consists of two coalesced volcanos: a typical shield volcano on the northwest end and a low, linear fissure volcano on the southeast end. Subtle differences in lava chemistry confirm that there are two volcanos here, and indicate that each has its own plumbing system and each taps a different melting zone in the mantle.

Sullivan Bay Highlights:
During a volcanic eruption in the early 1900’s, this area of Santiago was covered with flowing lava. Today, the hardened fields of black rock create a geologic wonderland. The glazed black rock gives the impression of the still-molten lava, as every ripple, swirl, and bubble in its surface has been preserved. Only the occasional pioneering Mollugo plant gives a clue of the time needed for species to colonise such an expanse.

Sullivan Bay is especially fascinating for those who are interested in geology and volcanology. You can take a spectacular walk over the uneroded, black lava flow covered with lava bubbles and tree-trunks mold in the surface. There are two small beaches where turtles come for nesting.

Excursion options include enjoying a cool early morning walk at this amazing site.