Water-themed sculptures guard this unusually square structure.

The wreck of a B-29 Superfortress now stands as a memorial left in the moors.

This lone tower casts an outstretched shadow over the site of a once-wealthy Knights Templar preceptory.

One of Edinburgh's most popular works of street art is located well off the beaten path.

One of Bristol's best-hidden gems has ties to Lord Byron, whence it became the nation's first reformatory school for girls.

Over a thousand musical instruments are on display, from bagpipes and harpsichords to drums and the sinuous serpent.

A shiny sculpture celebrating the mighty mollusk.

A historic fortification critical to Anglo-Scottish conflicts now serves as a bed and breakfast.

These ruins of a medieval church are full of architectural mysteries.

Over a decade ago, painted penguins mysteriously appeared around Berwick-upon-Tweed for no apparent reason.

An abandoned, desolate train tunnel that was used during World War II.

This Scottish manor house is a lush relic from the life of a literary great.

Hundreds of huge, centuries-old horseshoes adorn the walls of this nontraditional 12th-century castle.

This unique bridge curls up like a caterpillar to let boats pass and then unfurls again to span a small canal.

A visionary precursor to the Internet made of index cards.

Each spring, a dreamlike carpet of bluebells overtakes the forest floor.

Wander among free-roaming storks at the sanctuary that helped save them from local extinction.

Germany has its very own Centralia, whose spark remains attributed to "spontaneous combustion."

Built to test magnetically levitated elevators, the tower also boasts Germany's highest visitor platform.

One of the most well-known city festivals in the world.

A colossal sculptural lion built by the same man who designed the Statue of Liberty.

Along the Rhine, about a mile from the historic Munster, learn the heartrending story of two lovers torn asunder, cast into unknown layers of time and space.

Obscured within a ring of trees, this abandoned World War II relic hides on a German hillside.

An 11th-century fortress home to one of the most influential royal houses in medieval Europe.