A 16th-century castle unexpectedly nestled within a post-war housing development.

This Scottish museum is the only one in the world to focus not on one religion but all of them.

Climb this overlooked gem's spiral staircase and you'll be rewarded with spectacular views of Glasgow.

This Italian stadium makes liberal use of fascist statuary to evoke classical sporting arenas.

Also known as the Square Colosseum, this building is a prime example of fascist-era rationalist architecture.

A detailed pachyderm supports Rome's smallest Egyptian obelisk.

Installed in an act of one-upsmanship, the annual sundial in this church is also a symbolic victory for the Gregorian calendar.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

The spot where the fascist dictator made some of his most famous speeches including declaring war on Britain and France.

This hill made entirely of ancient Roman jars was simply a garbage dump to the people of the time.

More sculpture than building, this architecturally significant temple was built on the spot of Saint Peter's crucifixion.

A Nesting Doll of Churches.

Architectural monsters are devouring this palace's every door and window.

At the crypt of St. Mary of Eulogies and the Dead you are left alone to ponder mortality among piles of skulls.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

Architectureal fantasy quarter of Rome.

This neighborhood of futuristic ball houses looks like an alien settlement in a science fiction film.

The ruins of this medieval castle in Northern Ireland have inspired artists from C.S. Lewis to Led Zeppelin.

The sculptural remains of the last home of a legendary Dada artist.

Now famous as the "Harry Potter bridge," this impressive concrete viaduct has long been an icon in its own right.

This 1,300-year-old marker is one of the finest and most complete early Christian crosses in Scotland.

This restaurant was removed from the famed sister ship of the Titanic and placed within a hotel.

This iconic 1,000-year-old medieval castle is a favorite of the film industry, most notably as the location for Hogwarts in Harry Potter.