Table of Contents
The world needs parks. Whether they're slivers of green in a crowded city or 20,000 square miles of designated wilderness.
Today there are almost 400 units in the parks system, and nearly 300 million Americans alive to enjoy them.
Why would any city go to the bother and expense of growing green space in an urban environment?
Many of the compounds absorbed by the body stay there for years–and fears about their health effects are growing.
Pyramid of Death
At the Pyramid of the Moon in central Mexico, humans and animals were buried alive.
Visions of Earth
Each month, National Geographic features breathtaking photographs in Visions of Earth.