This obscure walkway links Edinburgh’s Old Town with one of the city's prime vantage points.

This abandoned airplane hanger is said to have once been a top secret launch facility.

A former bank seized as a sniper vantage point during the Bosnian War is now a secret graffiti art gallery.

This museum preserves the hand-dug tunnel that kept Sarajevo afloat during the Serbian siege.

A war-torn Olympic relic is being overtaken by graffiti and nature.

The place where World War I began.

A number of craters left by fatal mortar strikes have been filled with red resin to remember those lost during the Siege of Sarajevo.

A monument on the pavement marks the spot where two cultures that shaped Sarajevo come together.

Inat Kuća, or "House of Spite," is more than just an oddly named restaurant.

This historic timepiece is thought to be the only public clock in the world that keeps lunar time.

Oriental bazaar in the heart of Sarajevo.

The bombed out remains of the old church were kept intact next to the new one, as a reminder of the futility of war.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

This memorial to the victims of the Romanian Revolution of 1989 is often compared to a potato on a skewer.

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."

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

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

The home of possibly the least-loved U.S. president stands as a sort of unpopular Monticello.

This strange building looks like a medieval fortress crashed into a 1960s Brutalist office block.

A church filled with the bones of hundreds of virgins martyrs—or so they say.

This concrete church spent a period of its history as a World War II bunker.

The Bauhaus-style former industrial complex is considered the world's most beautiful coal mine.

This "floating railway" is one of the world's oldest monorail systems.