Scattered throughout London are ancient remnants of the city's former bounding wall.

The remains of Crystal Palace Great Exhibition of 1851.

The quaint little store that is said to have inspired a famous Dickens novel was only given its name after the book was released.

An unusual round church in London with a Templar past.

The ruined doorway is a portal to the building's turbulent and torturous past.

The railway carts travelers to central Athens's highest peak, which offers stunning vistas of the city.

This gem is often wrongly overshadowed by the larger, newer Metropolis church in Athens.

An ancient octagonal weather station named for the eight Greek gods of wind.

The second-largest Jewish temple in Bulgaria was deserted after World War II, seized by the communist government and then abandoned again.

A spectacular Bulgarian cave resembling a devil's head with a waterfall rushing down its throat.

The 700-year-old fortress was the site of Count Orlok's castle in "Nosferatu."

This elaborately decorated, fairytale-like Romanian royal palace is one of the most striking castles in Europe.

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."

A fire once nearly devoured this gorgeous 14th-century Gothic cathedral.

The European towns of Brașov and Râșnov each have proud signs reminiscent of the Hollywood sign.

An abandoned Byzantine fortress and notorious prison.

Ancient serpentine sacrifice holder that has stood the test of time.

A fountain standing as a testament to a doomed alliance.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

A marvel of Byzantine engineering under the streets of Istanbul.

The "Prussian Versailles" that is as glorious today as when it was built.

A theatre built to house the rowdy Oxford graduation ceremonies became the stage for a debate about God's existence.

One of Europe's oldest libraries.

This narrow Ghent alleyway is an officially sanctioned street art tunnel.