A startling, centuries-old subterranean marvel hides in plain sight.

Temples adorned with intricate, erotic sculptures make up one of the "seven wonders" of India.

Modest by day, illuminated majestically at sunset.

A complex of six forts embedded in the Rajasthan hills.

An extraordinary "City of Caves" carved from solid stone.

A palatial sculpture park was built illegally and in secret by a self-taught artist over 36 years.

The remains of what was, not so long ago, the world's largest city.

Once an indicator of social class, the color blue has come to define this city on the edge of the Thar Desert.

More than half of this Indian palace is drowned but it looks all the more spectacular for it.

The 953 windows undoubtedly make this the world's most beautiful screened porch.

Thousands of exquisitely carved stone water storage wells, hundreds of stone steps fill this exquisite medieval stepwell.

The longest living non-clonal organisms on Earth.

Over 3 miles up in the Himalayas this pass is one of the highest drivable roads in the world.

This long-hidden space above Westminster Abbey now displays the battle gear of the legendary King Henry V.

Seven beautiful 1,000-year-old rock-cut Buddhist statues.

A former bastion of Rajput chivalry, this massive hill fort is the site of legend and tragedy.

This stunning 15th-century royal hill fort preserves the age of chivalry in Rajasthan.

This magnificent stepwell is designed as an inverted temple and adorned with 1,500 sculptures.

This peaceful Sikh gurudwara serves around 50,000 free meals every day within its gilded walls.

A mecca for India's Jains.

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.

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

This complex of vertically-excavated Buddhist, Jain, and Hindu monolithic temples in India's Maharashtra providence illustrates a spirit of tolerance characteristic of ancient India.