A tunnel with windows, so you don't miss out on the impressive views.

The fifth-longest natural arch in the world, and the longest outside China.

Settled by the Church of Jesus Christ of Latter-day Saints in 1859, this abandoned frontier town has appeared in several films.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

Traveling this mountain pass reveals quaint stone buildings, stunning Irish scenery, and a bridge said to grant wishes.

This hidden oasis features a stunning view of the Hudson River and the Palisades from a castle-like museum.

Blighted Irish field and the ruins of a 19th-century cottage on the edge of urban Manhattan.

Mountain where Jesus was first tempted by the Devil.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

This semi-secret storybook hedge maze is also the oldest garden in the city.

The ancient past meets the retro-future at these dinosaur tracks that are protected by a geodesic dome.

The former home of Samuel Clemens and family remembers the happiest period of the author's life.

Public outcry led to this bridge's unique character which celebrates a giant frog battle and also sewing.

This abandoned psychiatric hospital once housed more than 4,000 patients in the middle of a quaint New England town.

The once abandoned ruins of a Victorian beachside amusement park are now back in working order.