This unassuming bookstore in the heart of Madrid is one of the oldest in Spain.

A must for film lovers in Madrid and home to the Spanish Film Library's projection space.

Blue-green pools and smooth stones comprise one of Spain’s most idyllic hidden wonders.

This small museum tucked within a subway station holds pieces from Madrid's past.

A small museum displays some of the artifacts discovered during a subway station renovation.

One of the best examples of the modernist movement in Madrid.

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

Legend says these colorful, invasive residents are the descendants of birds released by Jimi Hendrix.

This ancient Egyptian obelisk still bears the wounds of World War I.

An unusual ode to the late Irish playwright, complete with a squiggly bust and coffin-shaped bench.

An architectural oddity hides in plain sight on this iconic London bridge.

The Tudor-style cottage in the middle of the square is not quite what it seems.

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

The "lost friend” is the most famous of the six moai statues that were removed from Easter Island.

The rose garden in Regent's Park where Pongo and Perdita met for the first time in Disney's "101 Dalmatians."

The library houses an incredible collection of some of the world's most impressive books and manuscripts.

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

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

A community of artists and entrepreneurs seeks a simpler life on London's waterways.

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

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

A statue marks the exact spot where The Boy Who Never Grows Up made his first literary appearance.

This massive collection of British military artifacts includes the heartbreaking personal letters of the men in the trenches of WWI.

Thanks to modern navigational tools we now know that the true prime meridian runs through a park next door.