The "Greatest Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

A flight of this "ghost staircase" has 40 steps on the way up, but only 39 steps on the way down.

Get past the gatekeeper's apartment and enter an elaborate hoax of a restaurant with a Masonic feel.

Gorgeous views of Italian mountains and valleys form the backdrop of this unique open-air theater.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

Remnants of the city's Soviet history hover over this modern fast-food outlet.

Inside a beautiful Indian temple is a seemingly magical floating pillar that doesn't touch the ground.

This giant seated Bhudda of Healing dates to the 1780s.

A magical place that lets you play in and explore the world of Studio Ghibli.

This quirky little private museum is home to more than a thousand stones, carved by nature, that resemble human faces.

A disconnected rotary phone for "calling" lost loved ones offered a unique way of dealing with grief in disaster-stricken Japan.

This ancient burial site was once thought to be the home of a race distinctive to Ainu folklore.

The development of this cliffside waterpark is representative of Mexico's history of co-op tourism developments.