This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

This whimsical group of statues is a favorite of children who love to climb all over Lewis Carroll's beloved characters.

Mysterious 500-year-old tapestries depict a unicorn hunt.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

Elevated freight railway turned wildly successful urban park.

Manhattan’s Battery Park has a whimsical carousel full of spinning, glowing fish.

Dodge prohibitionists and slide through the telephone booth in Crif Dogs.

A crumbling hospital from the 1850s on Roosevelt Island.

Meet the world's longest tapeworm in a collection that really gets under your skin.

A magical place that lets you play in and explore the world of Studio Ghibli.

An abandoned Cambodian resort that mirrored the downfall of the country as it was happening.

Handcrafted thermal spa washes away each night with the tide.

This huge metal monument is slowly being stripped to its concrete skeleton.

Yugoslavia's biggest underground airport lies in ruins.

This memorial park stands on the site of one of the largest mass executions of the Second World War.

Where the lovelorn find a home for their sentimental keepsakes.

Hundreds of thousands of concrete bunkers crowd Albania long after the fall of Communism.

Structure built from the skulls of vanquished foes.

This brutalist monument is inscribed with 9921 names of Yugoslav partisans who perished during WWII.

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

Giant WWII fortresses that fired 8,000 rounds a minute, now home to thousands of pigeons.

150-year-old satirical tableaus made from stuffed frogs.

A nearly 500-year-old sculpture depicts a man eating a sack of babies, and no one is sure why.