Longest road tunnel in the world features an air treatment plant and the illusion of daylight.

One of the most breathtaking railways in Europe also takes one of the steepest climbs, from fjord to mountain plateau.

Walk behind a 50-meter-high waterfall.

This floating sculpture of ice is a poignant reminder of nature's power.

The design of this beautifully crafted building was inspired by Norwegian glaciers.

Macabre astrological automaton clock dating to the late 1400s.

Inside India's oldest mosque, a lamp is said to have burnt for 1,000 years without going out.

One man's exploration of the human form, including the bizarre and delightful "Man Attacked by Babies."

At 8,000 feet, the world's highest tea estate draws visitors for both its products and its panoramic views.

This ancient Hindu temple is covered in thousands of colorful statues and has a long mythological history.

This bright pink Gandhi memorial was built so that sunshine hits a specific spot on his birthday.

A towering work of stone and philosophy that was constructed using ancient Hindu science.

Although damaged beyond recognition, this stone god is still said to bring good luck to those who tap on him with a pebble.

An enormous pair of straw sandals woven in the traditional way—to keep demons at bay.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

A tree that grows parallel to the ground was declared Brooklyn's "crowning curio" by the poet who saved it.

This elaborate tunnel is the first structure composed of cast concrete in the United States.

This mile marker stands at the unofficial end of a highway built to defend the United States from a Japanese invasion during World War II.

The drama of nature in full effect in this Nevada State Park.

City Council meetings still happen in this historic building, impeccably preserved on the inside.

The longest spit in the United States ends at a lighthouse in the Strait of Juan de Fuca.

An abandoned network of military bunkers and tunnels open for anyone willing to descend into the darkness.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

Commemorating the spot where the famous scientist fed his pigeons.