Alvin, an underwater vessel, travels across the floor of the Caribbean Sea. Alvin began working in 1964 and was the first deep-sea vessel that could carry passengers.
Photograph by Emory KristofÂ
Volcanoes
Take a look at pictures nature at its most explosive.
Homework Help: Your one-stop research center for pictures, articles, maps, and more on our top subjects—perfect for reports, presentations, and more!
Sharks
Beware, these large fish are sure to scare!
Planets
These pictures are out of this world ... seriously.
Ancient Egypt
Take a look at ancient artifacts.
Cave Exploration
Look at pictures of the deepest and darkest caves.
Tropical Rain Forests
Look at lush and beautiful rain forests.
Underwater Exploration
Dive deep down to see what's at the bottom of the earth's many bodies of water.
© 1996-2008 National Geographic Society. All rights reserved.