The oldest arboretum on the Dalmatian coast doubles as the gardens of Kings Landing in "Game of Thrones."

Now harmless, this looming post struck fear into the heart of medieval troublemakers.

Longest fortress system anywhere in Europe.

Gargoyle head that brings good luck.

A musical instrument played by the sea.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

Where the lovelorn find a home for their sentimental keepsakes.

An ancient Scottish rock formation said to be the gravesite of a giant remains ensconced in legend and intrigue.

A memorial to Wellington's well-loved, well-traveled wharf dog.

This hidden rooftop garden in downtown London offers a quiet respite from a bustling city.

These mysterious Viking chess pieces spent centuries hidden on a remote Scottish island.

Graffiti from the 16th and 17th centuries cover the walls of this part of the Tower of London.

These ornate arches show how the course of the River Thames has changed.

The fierce beast perches atop a pedestal marking where the historic City of London gates once stood.

Historic church where a number of Shakespeare's actors are buried.

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

Murals of the wild parties once held on the frozen River Thames.

There's an exclusive Beefeaters pub hidden in the Tower of London.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

The majority of the museum's large collection is held in a storage space open to the public a few times a year.

You'd never know the houses at 23-24 Leinster Gardens were fakes—until you see the train tracks on the other side.

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

This one has sailed five times as far as Sir Francis Drake's famous ship.

A network of concealed passageways lies within a busy London Underground station.