UN System-Wide Earthwatch: Northern Mariana Islands
- Environmental information and statistics, including details for individual islands in the group.
- http://islands.unep.ch/CLY.htm

The Mariana Trench
- Explore the deepest part of the Pacific Ocean and the deepest location on Earth.
- http://www.marianatrench.com

Challenger Deep
- Challenger Deep got its name from the British survey ship Challenger II, which pinpointed the deep water off the Marianas Islands in 1951. Also called the Marianas Trench.
- http://www.extremescience.com/DeepestOcean.htm