150 or so scrounged-up lamps, chandeliers, and lanterns light up this alley in central Athens.

This hidden art nouveau gem was designed by an architect in search of a national style.

Tucked away near more famous landmarks lies a statue meant to symbolize the confluence and continuing development of human culture.

Once the home of a hermetic monk, this cave now houses a small church.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

This Budapest bar allows drinkers to leave their mark on the walls, floor, and even ceiling.

A black cat protests the City Guild in Riga's Old Town.

3,000 market stands in five former Zeppelin hangars.

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

A solar-powered primary school inspires hope and experimentation in a country ripe for energy innovation.

Thousands of costumed dolls fill one of the world's creepiest museums.

Museum celebrating the ocean, with the largest wunderkammer dedicated to sea exploration.

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

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

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

Giant eggs, walls of bread, and nightmare surreality mark the largest collection of works by Salvador Dalí.

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

Mountain where Jesus was first tempted by the Devil.

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.

A reconstructed medieval gateway that was the magnificent entrance to the capital city dating back to 1037.

340-foot statue built to honour the Heroes of the Soviet Union.