Most-visited and most-photographed slot canyon in the American Southwest.

One of the world's tallest waterfalls wasn't revealed to the world at large until 2006.

This geometric feat is a testament to the Incas' mesmerizing architectural abilities.

The stones of this Incan wall complex fit together so well you couldn't fit a piece of paper between some of them.

Situated on a sacred Inca site, this 16th-century cathedral took nearly 100 years to build.

For more than half a century, an enormous feline has watched over this London neighborhood.

The world's first fully-fenced urban ecosanctuary is a haven for New Zealand's rare and endangered species.

This massive complex is made up of hundreds of smaller temples that date back to the ninth century.

The large collection of pre-Columbian pottery might make you blush.

The outside of this exposed Moche pyramid is covered with striking colorful adobe friezes.

Some of the clearest water anywhere in the world.

Deep in the Guatemalan jungle stands an ancient pyramid that once marked the reign of a king.

Sparkling, calcite-covered skeletons of children who may have been sacrificed to appease an angry god.

Holy Hindu shrine in an enormous, monkey-filled limestone cavern.

Kakadu National Park is known for its stunning beauty and its rock art, which represents the longest historical records of any continuous civilization on Earth.

Let these towering termite-building structures tell you where to go.

This mini version of the famous Bohemian castle was lovingly built by a Czech immigrant and mineworker.

Tracking the 1,500-year history of Korea's star cabbage.

Huge stone depressions which may have acted as an Incan agricultural experiment.

The final resting place of the poets Shelley and Keats.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

This strange geological landscape erupts with sudden bursts of water.