This 1967 experiment in modular architecture was designed to be a new model for urban living.

Spanish architects used seized Muslim gravestones to rebuild parts of the fortress.

This sweet-toothed bear searching for snacks has been a symbol of Madrid for decades.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

Carvings in Turkey's Marble Road may have directed ancient Romans to a hidden brothel.

The alleged house of the Virgin Mary is tucked away in a park and nature preserve on Mt. Koressos in Turkey and is holy to both Catholics and Muslims alike.

Legend says this sacred tree was a gift from goddess Athena.

Knoxville’s architectural icon was the symbol of the 1982 World’s Fair, even catching the googly eye of Bart Simpson.

The floor of this spectacular Baroque sanctuary is covered in memento mori.

Dynastic Home of the De Piro Family.

This steep cable railway has been hoisting passengers in the heart of Québec City for over a century.

This lovely, if imposing, piece of Canadian gothic is possibly the most photographed hotel in the world.

This chilly Canadian hotel has a four-month lifespan due to the unusual material it's made of.

The longest enclosed pedestrian bridge in the world spans 14 lanes of traffic and six rail tracks, all while lighting up the night sky.

The remains of a once-famous hotel that also acted as an artist colony.

Canada's largest dinosaur skeleton was hidden away in storage for more than 40 years.

Now a public art piece, this curious metal feature originally advertised a tinsmith's services.

Eighty million natural history specimens call this gargantuan museum home.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

A local student's chance encounter with Keith Haring led to the creation of one of Europe's largest murals.

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.

The only museum with its curator—and her pets—buried inside.