The tallest sea cliffs on the Southern Hemisphere are a climber's worst nightmare.

The only pollutant in the clear blue water is sunscreen.

This gracefully curving formation looks like a massive wave that was suddenly turned to stone.

An abandoned railroad tunnel is now filled with bioluminescent bugs.

A rapidly disappearing glacier filled with extinct grasshoppers, perfectly preserved in the ice.

This beautiful ancient site is dotted with perforated sandstone pillars considered sacred by some Native American groups.

This off-the-beaten-path abandoned town is a relic of Montana's silver mining boom.

New fungal and bacterial species call this deadly lake home.

This amazingly preserved Gold Rush town is a historian's dream.

This angular Dwarven tunnel cuts through a mountainside in Glacier National Park.

A sculpture made of 10 Cadillacs as a monument to the "Golden Age" of the American automobile.

A lovers' beach, tucked below the surface of the island, provides a safe haven for romance.

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

This tiny square mile of Canadian sand was once considered the world's smallest desert.

Roadside collection of 65,000 signs.

The biggest museum dedicated to insects in North America, one of the largest in the world.

This 1967 experiment in modular architecture was designed to be a new model for urban living.

Designed by Buckminster Fuller, this relic of the 67 Expo survived fire and ice.

This engineering marvel is the longest bridge in Canada and one of the longest spans in the world.

Rusty red sands line the shores of this Canadian Province.

This extensive nuclear fallout shelter built from 42 school buses could house 500 people in its tunnels.

Stunning views over Ontario's old-growth pine forests.

A boardwalk winds above this beautiful bog full of wildlife and a rare type of turtle.

Canada's oldest railway tunnel is illuminated in a rainbow of color as it passes under the streets of this small city.