An alley covered with 20 years of bubble gum.

A modern reimagining of a medieval city gate.

Built by crowdsourcing, this wooden foot bridge saved a part of Rotterdam that was languishing in wait of city funding.

A dramatic art installation features a BMW flying out of a building in Rotterdam.

A huge teapot illuminates a home for the elderly.

A statue of the second-tallest Dutchman in history.

These lights mark the area of Rotterdam that was bombed and burned in 1940.

Four giant movable street lights decorate this modern Rotterdam square.

Richard III supposedly disposed of his nephews' bodies here in an effort to seal his claim to the throne.

Graffiti from the 16th and 17th centuries cover the walls of this part of the Tower of London.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

These wire animal sculptures commemorate the exotic inhabitants that once called the Tower of London home.

Hear the quietest sound from across the dome.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

The best place in the world to buy tinned fish.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

Climb inside an iron crystal magnified 165 billion times its normal size.

Meet the bronze beloved pet to a family of famous peeing statues.

A little sculpture with a large wardrobe.

Three floors of musical instruments coming from all corners of the world and hundreds of years of musical history.

Cozy basement bar sports an inventory of over 2,000 beers.

Brussels' favorite peeing boy has a sister.