Singapore's landscaping project is home to 18 incredible Supertrees.

A fantastical 13th-century fortification sandwiched by a modern hotel in central Brussels.

A little sculpture with a large wardrobe.

This collection of over 50 murals celebrates Brussels' rich history as the self-proclaimed home of the "comic strip."

Scale model of St. Peter's Cathedral (Rome) in the middle of a small Dutch town.

Some 80,000 Delft Blue tiles line the inside of this Amsterdam walkway.

Amsterdam's former hotspot for public executions and dissections.

A mammoth WWII anti-air defense tower has been repurposed as a hotel with a rooftop garden.

Once the tallest building in the world, this abandoned church is now a monument to the destruction of WWII.

You've probably seen these distinctive orange-tiled columns on the big screen.

Metro station with a claim to rock n' roll fame.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

Cold war icon and onetime "hole" in the iron curtain.

Berlin's old airport.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

A fascinating insight into daily life in the Eastern Bloc.

"Holy Wisdom" overlooks the city that became its namesake.

A striking symbol of the Bulgarian capital.

A gorgeous, Gaudí-esque stairway constructed in the city of Istanbul by a prominent Jewish family.

Legend says if you stick your thumb in the hole and it gets wet, your wish will be granted.

A small etching on the white marble parapet was written in runic script by a Viking mercenary.

The ornate miniature mansions were built for Istanbul's feathered residents.

An abandoned Byzantine fortress and notorious prison.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.