Earthquakes. All you want to know about earthquakes.
http://www.gsrg.nmh.ac.uk/

The Mineral Gallery. Explore rocks and minerals. Includes pictures.
http://mineral.galleries.com/default.htm

Earthquakes for Kids & Grownups. From the U.S. Geological Survey. Learn about past, present and future predictions for earthquake activity. Includes neat facts about quakes, science fair project ideas and answers to frequently asked questions about earthquakes.
http://earthquake.usgs.gov/4kids/

Primordial Soup. The history of life on earth: paleontology, wonderful graphics, and interactive components.
http://www.primordialsoup.com

RiverResource. Find information on rivers around the United States.
http://www.riverresource.com

Volcano World. Find details about volcanoes, their eruptions, and more. Part of a NASA project.
http://volcano.und.nodak.edu/