The tree lined, approximately 500 x 700 m, Caldeira Seca pumice ring (center) on the floor of the Sete Cidades caldera, with Lagoa Azul and the northeast wall of the caldera in the background. The southeastern flank of the Calderia do Alferes is seen in the upper left. Caldeira Seca formed during a 15th-century phreatomagmatic eruption in which large amounts of pumice ash, lapilli and blocks were erupted.

Photo by Rick Wunderman, 1997 (Smithsonian Institution).

This image is made available under the Public Domain Dedication CC0 license, but proper attribution is appreciated.

Sete Cidades