The walls of America's oldest masonry fort famously "swallowed" cannonballs.

The haunting complex honors the millions of Ukrainians who died in the forced famine under Soviet rule.

This derelict superstructure was a very important warning system for the Soviet military.

One of the most poignant ruins of the Chernobyl nuclear disaster, the local football team's stadium has been quickly reclaimed by nature.

This historic folk art garden contains a nightmare tower that claims to be the world's largest concrete totem pole.

This expansive bridge in the Canadian wilderness was originally just built for friends.

A powerful tribute to the victims who suffered under Ethiopia's most devastating regime.

A popular rock that acted as a waymarker for American pioneers.

Long before guestbooks and hotels, frontier travelers signed their names on this rock face.

The first declared National Monument in the United States.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

A beautiful footbridge with over 2,000 glass sculptures along the walls and ceiling.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

Five candy-colored villages on the Italian Riviera.

Largest Roman Catholic church in North America.

A Viking-style brewpub named for a Norse sea giant, in the heart of fjord country.

One of the most breathtaking railways in Europe also takes one of the steepest climbs, from fjord to mountain plateau.

Civil War Fort on an island in the Boston Harbor.

Breathtaking and huge 430 year old maps of Italy.

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

A whimsical bridge adorned with decorative dragons.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.