An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

This massive boulder was hurled into a Zurich church when a gunpowder depot was struck by lightning in 1652.

An homage to Jackie Gleason's bus-driving character from 'The Honeymooners.'

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

One of only two commuter aerial tramways in the United States.

A former insane asylum despised by Nelly Bly and Charles Dickens is now fashionable apartments.

A little lighthouse in New York City, surrounded by mysterious stories of insanity-driven construction.

A crumbling hospital from the 1850s on Roosevelt Island.

A remnant from the golden age of aviation still in use today, Pan Am's Clipper service took off from this Art Deco gem.

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

A retired subway car stands alone in a field in the middle of Queens.

A young woman's senseless murder led to the controversial psychological theory of the "bystander effect."

The preserved arm of a third-century sorcerer is believed to have the power to lift curses and spells.

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

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

This once-derelict building is now one of the most beautiful bookstores in the world.

Romania's triumphal arch looks out over Bucharest.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

This ancient hydrological marvel is now the base of a modern outdoor cinema.

The art museum is decorated with creatively remodeled pre-Nazi swastikas.

This building featuring Brutalist architecture has a rich media production history.

This 1000 year old relic-filled cave monastery and UNESCO World Heritage Site also hosts an amazing micro-miniature museum.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

This extinct shield volcano is the lightning rod of the Cascades.