One of the oldest scientific gardens in Britain, containing more than 13,302 plant species in its core collection.

Come for the oysters, stay for the priceless art honoring inventors across history and Scotland's favorite outdoor sports.

One of Antoni Gaudí’s earliest buildings, built between 1886 and 1890 for the industrialist Eusebi Güell.

Saint Joseph was said to heal the deaf and blind, but it was a much smaller miracle that got him canonized.

One of Antoni Gaudí's least-visited works, an homage to Catalan patrimony that mixes neo-Gothic with Modernista forms.

The former 1920s mansion of a prominent Catalan developer was used as the Soviet Embassy during the Spanish Civil War, and there is still a bunker below the garden.

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

This house's itty bitty size means no humans allowed.

Read a book with a glass of wine at this classically restored bar.

A once-secret library of Freemason history in Catalonia.

A beautiful but toxic fountain of mercury.

Hamburg's first legal sex work is relegated to a gated street that still does not allow pedestrian women.

Once the tallest building in the world, this abandoned church is now a monument to the destruction of WWII.

This industrial chimney looks rather out of place, isolated in the middle of an attractive woodland.

From Nazi chemicals to the CIA, this architectural marvel has played a fascinating role in German history.

Fantastic views and thousands of love locks.

The sweet story of how American cargo planes became known as "Candy Bombers" during the Berlin Blockade.

Carved fountains poignantly placed in parks and in front of special monuments.

The entrance to this Frankfurt subway station looks like an old tram car crashed into the concrete sidewalk.

A Jenga-style cylindrical tower of books that appears to go on forever.

This automated sculpture of two men peeing will spell out text messages with their micturition.

Buried five stories underground, this Soviet bunker is packed with gas masks and Cold War paraphernalia.

Tucked away in a Prague park, a statue beloved by romantics honors a poet so nice they buried him twice.

The tunnel's elegant proportions keep you snug with no claustrophobia freak-out.