There's a mini version of Iguazu Falls hidden in the Balkans, and it's got a rope swing.

Bridge that died in war and was resurected.

This picturesque monastery at the base of a cliff is a peaceful oasis open to all visitors.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

A bridge destroyed three times: once as a ruse, then in an actual attack, and finally for the movies.

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

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

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

The place where World War I began.

This 135-year-old weather station studied the effects of the climate on human health.

A World War II evacuation tunnel turned into a history display of Croatian state and people.

Amsterdam's former hotspot for public executions and dissections.

The Great Fire of London and the regulation of one-way streets both started in this alley.

The commemorative stone column conceals a secret laboratory.

The bronze uniforms commemorate the vital role of women during World War II.

Yo, Adrian!

This beloved marketplace mascot poops money and grants good luck.

The first American department store, and home to the largest operating musical instrument in the world.

The sounds of the world's largest fully functioning pipe organ dazzle shoppers at a Philadelphia Macy's.

This elaborate towering structure was once famed for its revolutionary height.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

A perfect circle of 24 mysterious holes dates back to prehistoric times.

A poignant museum dedicated to the history of the Dutch resistance against Nazi occupation

The first hospital in the New World.