The southern wall is the most prominent segment of the 11-km-wide Irosin caldera, and overlooks the flat caldera floor below the active Bulusan volcano. The northern caldera rim has been buried by the flanks of Bulusan and other post-caldera cones.

Photo by Chris Newhall (U.S. Geological Survey).

This image is made available as a Public Domain Work, but proper attribution is appreciated.

Bulusan