This deceptively salty lake looks like blushing pink lemonade.

This everlasting lightning storm may be the world's largest generator of ozone.

Keshwa chaca, among the last handwoven Incan bridges, crosses Apurimac Canyon in Peru.

An exquisite tunnel of cascading flowers.

The second-longest continuous wall on the planet protects a hidden secret in the deserts of India.

Spanning the El Chorro gorge, this pathway used to be one of the most dangerous crossings in the world.

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

Climb to the top of the world's largest seated bronze Buddha.

This red lake 4,000 meters above sea level is home to rare flamingos.

An emerald-green grotto just a short trip from Austin.

The rocks in this arid basin leave trails of movement behind them.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

In paradise, feral pigs have claimed an island all to themselves.

World's strongest whirlpool.

A single tree's 2,800 aerial roots give the appearance of a complete forest.

Perfectly preserved ancient monastery in an impossibly dramatic location on a rocky island in the Atlantic.

On the outskirts of a desert trading village high on the Andean plain, steel giants have been destroyed by salt winds.

Once thought to be the oldest living tree in the world, Methuselah was germinated before the Egyptian pyramids were built.

Sculpture designed by Turkish artist and professor Mehmet Ali Uysal.

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

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

Rome's semi-secret peephole vista is also a former Crusader stronghold.

Abandoned railway line circling the city of Paris.

A working steam clock, one of only a few in the world, located in Vancouver's Victorian Gastown.