The only road through the heart of Glacier National Park.

A majestic hotel that also stands as a historic relic.

Fresh wooden posts have been added to ancient holes to recreate a primitive henge clock.

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.

The hotel where Martin Luther King Jr. was shot is now a museum dedicated to his work.

This rare triple-jurisdiction drawbridge passes through Virginia, Maryland, and Washington, D.C.

Long buried under the 20th-century landscape, this lift lock of the Alexandria Canal is the lone remnant of an ambitious early American transportation project.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

Pivotal home of Nobel Prize winner Pablo Neruda.

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

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

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

Xul Solar was an artist of alternate worlds, inventor of languages, and dreamer of utopias.

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

This beautiful fountain was sculpted by a female artist who was ahead of her time.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Every equinox this Maya pyramid puts on a spooky ancient light show.

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

A magical sinkhole on the Yucatán Peninsula is adorned with mini waterfalls and hanging vines.

A focal point of the Cuban government, this city square features one of the most iconic images in the country.

This bleach-white graveyard overlooking the ocean is accessed through a tunnel.

This colorful gate stands as an entrance to the walled city of Old San Juan.

On a clear day, you can see all the way to the Virgin Islands from the top of this observation tower built in the 1960s.

The world's brightest bioluminescent bay.