A trio of hidden hot tubs takes advantage of Iceland's natural geothermal vents.

This natural Icelandic fissure allows divers to swim right between two volatile tectonic plates.

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

Barça football fans might see the insignia hidden in a church window as a divine sign.

For one day every month Barcelona's Estació de França transforms into a market for model trains.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

Possibly the oldest church in Barcelona, this basilica has its pagan and Christian mythologies all mixed up.

Turntable anonymously received orphans, alms, and groceries.

One of the most photographed buildings in a city known for its Modernista architecture is an abandoned squat.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

This former Baroque palace on the historic Calle Montcada is a rare architectural gem and was once the meeting place of an aristocratic scholarly society.

Week-long block party becomes a competition for the best decorated street.

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.

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.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

This little museum is built on a theater that was once a wildly elaborate speakeasy.

Elevated freight railway turned wildly successful urban park.

Try not to get slimed in Tribeca.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

A phallic shrine to a princess goddess in Krabi, Thailand.

A tall karst islet popularized by 007.

A mile-long navigable cave adorned with stalactites and stalagmites reaching up to 65 feet tall.

This mountain sunrise is one of the most breathtaking views in Thailand, yet well off the tourist trail.