World's strongest whirlpool.

An intricately carved Viking church overlooks a glistening fjord.

The convergence of two currents makes this a surprisingly pleasant getaway in the Arctic Circle.

A serpentine highway twists and turns over the treacherous Norwegian Sea.

A sprawling Baroque park with 300-year-old hydro-pneumatic waterworks.

The medieval network of canals hidden underneath the city is opened to explorers each year.

A sulfuric martian landscape that looks far better than it smells.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

This hobbit-y little hot spring may be the oldest spring used by humans in all of Iceland.

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.

Iceland's "Smoky Valley" is a beautiful river that is shrouded in a constant cover of steam clouds.

This remote castle was built to be a wealthy businessman's palace of vice but is now simply a historic vacation cottage.

Museum about life, death, and cannibalism in the Stone Age.

A huge maze complex and whimsical miniature village in Tasmania.

This hidden rooftop garden in downtown London offers a quiet respite from a bustling city.

A tongue-in-cheek arcade where the games are based on everyday life.

This shop and gallery is a modern-day cabinet of curiosities, unassumingly positioned along an urban thoroughfare.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

A 1:20 scale piece of the Netherlands commissioned by a queen lets visitors take a stroll as giants.

The ruins of this Dutch castle sit atop a labyrinth of once-secret tunnels and passageways, dating back over 900 years.

This historic Amsterdam bar used to accept sailor's monkeys as payment.

A beautiful maze marks where three countries meet.

The twists and turns of this serpentine maze are over 170 years old.