One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.

Spanning the El Chorro gorge, this pathway used to be one of the most dangerous crossings in the world.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

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

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

Gaze upon chocolate sculptures depicting everything from chariot races to Gaudí's famous church at this shrine to sweets.

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

This semi-secret storybook hedge maze is also the oldest garden in the city.

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.

The original home of the Lego has a huge amusement park dedicated to the iconic plastic toy.

An enormous playhouse designed to look like 21 stacked Lego bricks, with another 25 million colorful Legos inside.

Hans Christian Andersen for the postmodern world.

Opulence and fantasy collide in this royal chair which is supposedly made with unicorn horns.

This sublime architectural marvel is a rare example of an expressionist church.

Danish tourist destination well known for open stalls where vendors sell marijuana on the street.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

Copenhagen's celebrated theme park and gardens.

This chimerical bridge/tunnel appears to dead end right into the sea.

An ancient Viking runestone hidden in plain view in Stockholm's old town.

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

The world's largest model of our planetary system.