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

This giant urban staircase was built to keep the city's brave fighting men from getting waylaid in the red light district.

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

There has been an astronomical clock on this spot since the 14th century.

One of a series of no-purpose kinetic artworks by Swiss sculptor Jean Tinguely.

The maze-like transportation hub contains abandoned areas, derelict stores, and a resident bat colony.

Originally used to sell brandy, the bull-shaped billboard became an iconic symbol of Spain.

Follow the original medieval paths that wind through this intriguing section of the city.

Mosaics, storks, and brothels—this ancient city has it all.

An awe-inspiring mosque in Morocco with one of the tallest minarets in the world.

Rome’s legendary peephole vista is also a former Crusader stronghold.

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

The Corinthian columns that towered over Abraham Lincoln’s inauguration stand proud.

This lovely picnic spot featuring thunderous jet landings is an aircraft spotter’s dream.

Enormous piles of historically significant stones, dumped by Congress in a forest, and abandoned for 60 years.

Though considered an eyesore by some, this boxy Brutalist high-rise plays a significant role in Sydney's past.

A collaboration of art and ornithology mourns the calls of Sydney's lost birds.