A star-shaped fortress town fort built in the geometric model of the Renaissance utopian city.

Croatia's towering concrete blossom grows from the site of a World War II concentration camp.

This stunning, out-of-the-way Croatian monument commemorates a community's uprising against occupying fascist forces.

The only museum with its curator—and her pets—buried inside.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

A tower marking the spot where Yugoslavia began its resistance against the invading Nazis stands neglected, but not quite forgotten.

This only museum in the world dedicated solely to mushrooms.

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

This Croatian fairytale castle is slowly falling apart thanks to years of neglect.

This modern, multimedia museum takes visitors on an evolutionary journey back in time.

Trimmed trees grow alongside the graves like topiary tombstones.

This one-time health resort was used by aristocrats around the world.

Famous landmarks and structures from across Italy fill this miniature park.

Macabre symbols of death and mummies on display set the tone of this Italian purgatory church.

A long-buried ancient ruin unearthed right in the middle of the city.

Thousands of colorful pirogues showcase ingenious craftsmanship at the largest fishermen port in Nouakchott.

This castle was once an Italian horror cinema star.

A galley-shaped memorial to the prisoners of an infamous fortress.

These pillars at the main entrance of this church are actually a hidden musical instrument.

This 6th-century church has the largest and best-preserved collection of Byzantine mosaics outside Constantinople.

An incredible mosaic-lined monument said to have held the remains of an ancient Roman empress.

Filled with goldfish swimming in a shallow pool of sea water, this ancient crypt is more wishing well than burial site.

Italian poet Dante Alighieri is entombed in this small mausoleum in Ravenna, and his hometown of Florence has never been too happy about it.