Colorful and chaotic stacked hotel in North Holland.

A Dutch clog company in the town of Zaandam loves the wooden shoes so much it made a museum for them.

The tallest waterfall in the Netherlands is a lovely, stepped feature that is only 50 feet tall.

The largest flower auction house in the world.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

The history and future of cannabis.

Cat art as far as the eye can see.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

Commemorating the spot where the famous scientist fed his pigeons.

The site of the deadly Triangle Shirtwaist Factory Fire.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

A nightly tradition fills the streets of Flogsta with a collective scream.

Mind-blowing carvings and fantasy ice scenes grace the largest year-round ice environment in the world.

Now a hotel, this former bank was the site of a robbery that spawned a psychological phenomenon.

The internet as provided by a James Bond villain.

The history of the tea trade is told in bas-relief on this historic pair of Boston doors.

Pompeii's less famous neighbor is still revealing her secrets.

The oldest volcanology research center in the world.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

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

Where once there was a train station bathroom, there is now this German burger joint.

Floating swimming pool within a moored vessel.