This nearly endless university hallway is home to a unique sunset known as "MIThenge."

In 1958, an MIT fraternity pledge laid down on this bridge and instituted a new, unique unit of measurement.

This record-setting hydraulic dam in the Montana badlands was one of FDR's most ambitious public works.

The formidable fowl can be found standing near an isolated hiking path.

A high school astronomy enthusiast designed this model of our solar system to be traversed on foot.

The sculpture's largest spire points directly toward the North Star.

This super-sized statue is the only public memorial to the deal that ended America's neutrality during World War II.

A morbid gateway to an Alaska town prides itself on the hunting history it represents.

A trading post in the North Pole where children send letters.

While only two of the ancient buildings at this site are actually churches this was one of the earliest Irish pilgrimage sites ever.

An unusual manor of stunning beauty, born out of a crippling disease.

A devastating booze inferno poured through the streets, claiming several victims who drank it.

His discovery kicked off the Gold Rush. One of the hands on this commemorative statue points to the spot where he found the precious metal.

One of Ireland's most infamous prisons for rebels including men, women and children.

A particularly disconcerting tribute to Irish martyrs.

These barriers stand as stark reminders of Northern Ireland's troubled past.

Northern Ireland's Brobdingnagian stepping stones.

This short bridge is the only thing connecting a tiny Irish island to the mainland.

An Iron Age fort on the edge of a seaside cliff offers a glimpse into an ancient, mystical world.

This fairytale-like structure is the last turf church ever constructed in Iceland.

Twisted girders are all that remain of an Icelandic bridge that was wiped out by a combination of volcanic heat and glacial floods.

The flow from this waterfall sometimes comes out of springs below its rim.

This fantastical waterfall is hidden in a cave located in a cracked cliff.

Along this wire fence, travelers have been leaving a particular memento since 2012.