The opening photograph shows Aniakchak Caldera. A volcano does not have to look like a pointed mountain. These ten landforms help curious readers interpret photographs, from broad shields to underground lava passages. The order is an editorial learning sequence, not a ranking of size or danger.
Compare outline, texture and position before naming a feature. Several can coexist at one volcano. Sources were checked on 6 October 2026; photos show past conditions. Continue observing landscapes with our cloud guide.
Source / photo: NPS / M. William · Public domain. Resized. No claim to original U.S. Government works.