Where commuters walk through remnants of an ancient Greek necropolis.

The ruins of an ancient Roman tomb hidden in the basement of a trendy clothing store.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

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

One of the most photographed buildings in a city known for its Modernista architecture is an abandoned squat.

This cemetery features modernist statues as strange as its name.

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

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

The celebrated eyesore created by starry-eyed sweethearts.

Claude Monet was baptized in this lavishly ornate Paris church.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

Notorious artist squat renovated into legal studios.

When you're a great Russian Tsar, even your vomit gets a statue.

A fantastical 13th-century fortification sandwiched by a modern hotel in central Brussels.

A little sculpture with a large wardrobe.

Meet the bronze beloved pet to a family of famous peeing statues.

Theme park featuring miniature replicas of European monuments.

Climb inside an iron crystal magnified 165 billion times its normal size.

A small Denmark town displays a pair of titanic jaw bones as their community symbol.

Dozens of musicians have planted trees in this Danish park, and donated songs to go with them.

Atop this electronic store resides a massive fighter jet.