The second-longest pier in the U.K. stretches a whole kilometer into the Irish Sea.

A six-ton wedding present for the King of the Scots.

Protecting the dead from opportunistic body snatchers.

The final resting place of soldiers' loyal canine companions.

A book bound in the skin of an infamous criminal, along with countless other specimens.

This 17th-century street hidden beneath Edinburgh was once a breeding ground for the black death.

Catacombs turned marketplace.

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

The small peaceful island off the Venice tourist circuit is where the city began more than 1,500 years ago.

An extensive collection of reliquaries containing the bones of saints housed in the largest Catholic church in Venice.

Go inside to really appreciate this 500-year-old technological masterpiece.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

A popular shrine where the Blessed Virgin allegedly appeared in 1830, displaying a holy armchair and two incorruptible remains of Lady Saints.

The celebrated eyesore created by starry-eyed sweethearts.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

Monument to a suicide protesting the Soviet invasion.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

This Prague museum collects brutalist relics and memories from the country's former Soviet rule.

The first museum in the world devoted to sexual gadgetry.

The hidden lair of an alchemist rediscovered in a 2002 flood.

Macabre astrological automaton clock dating to the late 1400s.

A museum dedicated to a secret military hospital hidden beneath a castle in Budapest.

Museum dedicated to the terror regimes of Hungary.