In upstate New York, gorgeous waterfalls and a watermill are slowly being reclaimed by nature.

All that remains of one of the Civil War's more deadly POW camps is a simple flagstone.

The little-known final resting place of one of America's greatest writers.

This formerly abandoned amusement park includes a classic carousel and a replica of Mark Twain's famous hut-like Elmira study.

The wooden octagon in which Huckleberry Finn and A Connecticut Yankee were born can still be visited in upstate New York.

This unacceptably tall building was the real reason for Washington, D.C.'s skyscraper ban.

Live data is transmitted from the Atlantic coast to instantly recreate the ocean waves in this fountain at the NOAA headquarters.

Washington's iconic carousel has a nice piece of Civil Rights history.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

The once highest point in China blends symbolic design with a kick of adrenaline.

This smaller cousin of the Forbidden City has gone from ancestral sacrifice to tourist's whispers.

The most famous location in China was home to whole dynasties worth of imperial rulers.

One of the world's largest ice festivals dazzles visitors for over a month with radiant sculptures and carvings.

This Tang Dynasty behemoth is the biggest Buddha in the world.

The western-most fortress on the Great Wall of China has gone from a strategic stronghold to a kitschy tourist carnival.

These layered sandstone mountains in China look like they are made of pressed crayons.

Snow-capped peaks, colorful waterfalls and stunning vistas on the edge of the Himalayas.

A celebrity from the late Cretaceous period.

This monument to a veteran of the Mexican-American War is one of only two in Manhattan that serve as an actual mausoleum.

A 19th-century politician who died after walking home in a blizzard is honored with this Manhattan statue.

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

The fanciest public restroom in New York City boasts fresh flowers, art, and a classical music soundtrack.

The rogue roots are gradually consuming some of the historic marble grave markers.

The national park was once a plantation estate.