From economic backbone of a community to deadly diving hole, these former stone quarries are now a park for rock climbers and graffiti artists.

This peculiar lake of pitch is so thick and viscous that one can walk on its surface.

The world's largest man-made underground caverns offer unparalleled underwater wonders.

This natural sea cave hides a small wonderland of natural turquoise beauty.

This pair of Australian "waterfalls" appear to be falling straight across the land.

A gothic palace of endless stalagmites and pseudoscorpions waits within one of the world's most beautiful caves.

This frequently-photographed waterfall takes only a short hike to visit.

Canyon walls shrouded in ferns.

Stroll through a wonderland of stupendous moss-covered trees.

A Hawaiian stairway to heaven—that you can't climb.

Every autumn, this hillside is ablaze with red summer cypress.

These azure waters were thought to lead to the Mayan Underworld.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

Monasteries on rock pillars, once accessible only by frayed ropes.

A swing to dangle you off the very edge.

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

A seemingly endless landscape of pure salt stretches far across Bolivia.

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

Dramatic river bend surrounds a natural red-rocked pedestal.

The sign at the garden gate reads: "These Plants Can Kill."

This Elizabethan hedge maze is one of only six in North America.

This country market harbors goats on its roof.

Friction between grains of sand cause a curious "singing" sound.

One of the world's oldest and most massive living organisms is a grove of quaking aspens.