Paris' linguistic guide to the international language of, yes, love.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

This plaque marks the former home of one of the first women physicians in the Netherlands.

This large copper bolt represents the benchmark for measuring sea levels in most of Europe.

A hidden church in a hidden courtyard tells the story of the Miracle of Amsterdam.

This massive mural by famed pop-artist Keith Haring was hidden for almost 30 years until its 2018 rediscovery.

This historic Amsterdam bar used to accept sailor's monkeys as payment.

The railway carts travelers to central Athens's highest peak, which offers stunning vistas of the city.

A delightful museum entirely dedicated to the tiny homes of dolls.

Warsaw's fantastically preserved gasworks...almost.

A marvel of technology a century ago, this disused power station now offers a lovely glimpse into the industrial design of the past.

A random tree outside a Budapest hotel has become a DIY shrine to the late singer.

Late at night, the bust of the "Dracula" actor was snuck onto the facade of this Budapest castle.

Museum dedicated to the terror regimes of Hungary.

A 19th century artistocrat's mansion, turned into a library, hidden in a modern library.

This off-beat, quirky communism-themed bar isn't afraid to poke fun at its history.

Residing along a busy thoroughfare, this sculpture urges passersby to consider the future.

A plaque hidden in the law faculty at Leiden University honors the first scientist to make liquid helium.

Once the world's biggest telescope, it was later used as a coat hanger by a famous Dutch astronomer.

Once housed in the towers of this Gothic church, this 17th century clock still ticks today.

This 11th-century castle sits so low you can't see it behind the surrounding buildings.

One of the Leiden's oldest pubs is also the birthplace of the Heineken star.

An eerie, derelict amusement park in Berlin.

This historic Dutch newspaper building is covered with media-themed details—and one unrelated oddity.