An artsy hidden staircase leads to breathtaking views of San Francisco.

The former private quarters and office of Dr. Sigmund Freud now hosts a museum housing the works of the founding father of psychoanalysis.

A small museum filled with over 1,000 clocks, and one particular clock calibrated to run until the year 9999.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

The very center of Paris is surrounded by a bevy of strange good luck rituals.

This massive library holds what was once the largest book collection in the world.

Formerly known as National D-Day Museum, this collection commemorates the battles of Normandy and WWII.

Once defending the city of New Orleans from invasion by sea, this fort faces an uncertain future.

The crumbling remains of a 19th century fortess.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

France's most famous cemetery, with some of its most curious tombs.

Abandoned railway line circling the city of Paris.

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

A Montreal deli that was so beloved that it was allowed to circumvent their laws of language.

Montreal's giant farmer's market is a foodie's best friend, especially in the winter months.

A grand Gothic Revival basilica with stained glass depictions of Montreal's religious history has only one soul resting in its crypt.

Museum dedicated to the terror regimes of Hungary.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

This controversial museum includes such detested exhibits as a chocolate suicide bomber and fecal-smelling digestion machine.