Provides information about cliffs, explaining what they are, how they form, and where they are located, and looks at the risks scientists take in their efforts to study and learn more about different types of cliffs.

Cliff building -- Cliff locations -- Cliff climbing -- Sea cliffs -- Cliff features -- Fossil cliffs -- Cliff top colonies -- Mountain cliffs -- Ice cliffs -- Cliffs underwater -- Crumbling cliffs -- Becoming a cliff climber -- Glossary.