This vast, water-filled underground labyrinth can only be toured by boat.

Modern-day cave dwellers carve elaborate homes out of volcanic debris.

A 1,500-year-old, 3-story subterranean city where ancient Persians took refuge in times of war.

The bones of two medieval royal lions were discovered at the historic fortress.

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

Ship-sized kinetic sculptural fantasy.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

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

Pop culture has helped to keep this iconic British building from being destroyed.

The Metropolitan Police refurbished the blue box (perhaps not coincidentally) the same year "Doctor Who" returned to TV screens.

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

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

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

A makeshift shrine to the late rock star is still kept up on the nondescript façade outside 1 Logan Place.

Catacombs turned marketplace.

An unusual round church in London with a Templar past.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

Be(w)ar(e) the moat around this historic Czech castle.

A turn of the century building boasting some of the most beautiful art nouveau architecture in Prague.

Steadily reminding Czechia of its past.

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

Macabre astrological automaton clock dating to the late 1400s.