On the wall of this medieval walkway, a symbol of the Spanish Inquisition.

The medieval woodcut-style artwork chronicles life in medieval London.

Originally built for London’s cab drivers, this bright green hut now serves anyone a hot drink or meal.

The first tunnel to be dug beneath a river, repurposed as an art and museum space.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

A labyrinth hides in plain sight at each of the city's 270 Tube stations.

Giant, friendly pelicans in Central London, the most unlikely of places.

The curios of pharmacist and collector Henry Wellcome.

The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.

This very ornate Victorian gateway seems completely out of place in the modern industrial city of Warrington.

The phone booths in this English town have distinctly milky hues.

This tidal island, a sacred site in early English Christianity, was the target of a notable Viking invasion.

A medieval setting reimagined into a unique art alley.

This free museum is building a collection of books that are banned, censored or burnt around the world.

Disused seaplane hangar gets a second life as the jaw-dropping home of Estonia's museum of maritime history.

An empty relic of the Moscow Olympics crumbles away in Estonia's capital.

Relics from an era long gone, sit idle outside this Estonian museum.

"There's nothing there," and other lies the KGB told us.

Only a fragment of this 15th-century Dance of Death survives today.

This medieval Estonian tower provides access to a series of tunnels that have been home to soldiers, punks, and fine art.

Walk along the medieval fortifications that have been protecting Tallinn since the 14th century.

The Guardian of Tallinn.

The oldest continuously operating pharmacy in Europe.

Architecturally stunning library serves as the hub of Finnish scholarly life and culture.