The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

A house carved into a rock in the 1940s.

100 massive sculptures in the Hudson River Valley.

Why have you never heard of the second most popular tourist site in New York?

Home to the infamous "Typhoid Mary" and the worst loss of life in New York's history prior to September 11, 2001.

This church on a Tohono O'Odham reservation has stood since 1797.

Red sandstone structures dominate this landscape, which has been inhabited for some 5,000 years.

The world's only teal arches exist in a city that cares more about its aesthetic than an Instagram influencer.

A living snapshot of a different time in America is preserved and maintained by a community of volunteers.

A spiritual vortex among the red rocks in Sedona.

Most-visited and most-photographed slot canyon in the American Southwest.

The humble tomb of an Argentine general, hand-built by his son using stones brought down from the Andes.

These small sculptures pay homage to the lovable star of an iconic Argentine comic strip.

A beautiful young girl said to have been buried alive in her coffin…

105-foot wide giant metallic flower blooms anew every day in the heart of Buenos Aires.

A bright little alley in La Boca is a part of tango history.

A series of waterfalls so massive they straddle the border of Argentina and Brazil.

This historic, palatial theater is now one of the world’s most beautiful bookstores.

A tower devoted to — and modeled after — the Divine Comedy.

Buenos Aires' city of the dead contains some very famous remains, including Eva Perón.

It was once nicknamed "the most bombed hotel in Europe."

These murals stand as reminders to the troubled history of this Northern Ireland city.

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

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