Global Volcanism Program | Image GVP-11732
A broad caldera, partially surrounded by clouds left of center, cuts the summit of San Carlos volcano. This a basaltic shield volcano forms the toe on the SW side of boot-shaped Bioko (Fernando Poo) Island. This NASA Landsat view (with north to the top) also shows neighboring San Joaquin volcano, with its smaller lake-filled caldera, at the right.
NASA Landsat 7 image (worldwind.arc.nasa.gov)
This image is made available as a Public Domain Work, but proper attribution is appreciated.