This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

This whimsical group of statues is a favorite of children who love to climb all over Lewis Carroll's beloved characters.

One of only two commuter aerial tramways in the United States.

Sniff the Titan Arum's rotting flesh.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

Home to items never before seen by the public.

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

A curious carving hides on a marble column in the Mosque-Cathedral of Córdoba.

Spain's unique Mosque-Cathedral has been a place of worship for both Muslims and Christians throughout its history.

The world's largest wooden structure.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

A lush indoor jungle fills this bustling Madrid transportation hub.

An ancient Egyptian temple in the middle of Madrid, Spain.

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

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

Old ships and machinery fill a historic harbor in the city that's home to Europe's largest port.

These slanted cubic abodes are a creative if odd solution to a zoning pickle.

Pilgrimage site for star-crossed lovers.

This bustling Italian plaza is built on the ruins of an ancient Roman amphitheater.

Fortified medieval tower house with lovely roof garden.

A 1,000-year-old church holds the bones of the Christian martyrs who died hiding inside it.

A long-buried ancient ruin unearthed right in the middle of the city.