Rebuilt remains of a temple to Roman god Mithras.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

This pagoda was once the central feature of a Buddhist temple that no longer exists.

Secret refuge and museum of the Duke of Florence.

The bears of Bern have been a city highlight for over 500 years.

This simple apartment may have inspired some of the most important theories in the history of science.

A nearly 500-year-old sculpture depicts a man eating a sack of babies, and no one is sure why.

During the summer months, giant teddy bears take over Paris near Les Gobelins metro station.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

A statue in the heart of Edinburgh honors a bear that served in the Polish military during World War II.

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

A 18th century graveyard and its astonishing cortege of macabre iconography.

This bronze statue of Martin Luther King was placed in the park without permission.

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

This museum housed in a former brothel explores the past and present of sex work in Amsterdam.

A public urinal so pretty, it was declared a national monument.

This impressive collection of rare books on ancient mysticism inspired author Dan Brown.

Lavish royal estate punctuated with heated greenhouses.

One fisherman has used his love of pebbles and shore to create a crazy garden of rocky art.

A replica of the steam engine that hauled Queen Victoria's Royal Train is on display at Windsor.

At just 51 feet and 10 inches long, it's the shortest street in England.

The spot where three Protestant clergymen were burned at the stake during the reign of "Bloody Mary."

The shop where the girl who inspired the beloved character once bought sweets is now a book-themed commercial curiosity.

Hidden in plain sight, this creepy sculpture watches from above.