A living descendant of the famous tree that helped Isaac Newton develop the theory of gravity.

A stunning architectural yet functional feat, towering over Oslo.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

The commemorative stone column conceals a secret laboratory.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

Macabre astrological automaton clock dating to the late 1400s.

A medieval wash house where people washed clothes in a river allegedly formed by the tears of a mourning nymph.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

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

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

A subterranean house of worship carved right out of the bedrock.

These airport hangars are now a bustling shopping center with only hints of its past still lingering.

The lost American era of gunfighters, bandits, Indians and steam trains is recreated in Sweden.

Despite dreams of constructing this fairytale mansion, Albert Gotthard Nestor Cedergren never saw its completion.

The world's biggest version of the popular Swedish souvenir.

Sweden's oldest street has not changed for nearly a millennium.

Enigmatic bug-like sculptures mystify drivers along a Swedish highway.

Sound travels strangely in this underground whispering gallery.

The celebrated eyesore created by starry-eyed sweethearts.

Vortex-shaped aquarium hosts Europe's largest school of piranhas and other ocean creatures.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

Copenhagen's celebrated theme park and gardens.

Sweden's southernmost point is located in this charming fishing village.