The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

This prehistoric sinkhole lured exclusively male mammoths to their death, much to the delight of science.

Four-story concrete hotel never opened to customers.

A building so large that it has its own weather.

This railroad and oil tycoon's lavish estate now stands as a time capsule of the Gilded Age.

A monument celebrating the idea of reaching inaccessible places.

A mega theme park-wax museum mélange containing all things biblical.

A black cat protests the City Guild in Riga's Old Town.

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

This shrine to the patron saint of Alaska sits on a small tidal island and was built from the land’s own beach stones.

A rare chance to get up close and personal with a 13-mile ribbon of ice near downtown Juneau.

The "Gateway to the Arctic" connects Barrow's indigenous population with the sea and its traditional industry: whaling.

Make your reservation to have coffee with some kitties.

A hugely vast Irish landscape of barren rock that stretches for miles.

Though they've since been renamed, these two streets hint at Dublin's darker days.

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

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

The oldest pub in Ireland may also be the oldest surviving bar in the entire world.

San Diego's most historic and haunted home.

North America's largest accredited model railroad museum.

These crudely shaped folk giants may be the the second most photographed statues in the U.S.

This Alaska library may be the only one in the country that allows you to check out pieces of taxidermy.

Buy your friend a drink or staple some cash to the wall for the next guy at the Salty Dawg Saloon.

Open day and night, a church with three pews and Bibles.