Thanks to Steven Spielberg's 1977 film "Close Encounters of the Third Kind," popular culture might forever associate this geologic wonder with the strange and the otherworldly. Indeed, in that movie, the 1,000-foot-high monolith serves as the landing site for a massive alien mothership that releases human abductees. Today, rock climbers ascending the Tower's smooth sides and basalt columns are the only ones getting high off the ground at the Monument, a preserve operated by the National Park Service.

As the only town along Nevada State Route 375—aka the Extraterrestrial Highway, 98 empty miles that run near the top-secret military base known as Area 51—Rachel stands as the region's epicenter for all things alien-related. Visitors' first stop in the town of less than 100 is often the Little A'Le'Inn, a bar and restaurant with extraterrestrial-themed mixed drinks, T-shirts, trinkets and beer-sipping locals who might point you to preferred UFO viewing areas. The town hosts events year-round the likes of the E.T. Full Moon Midnight Marathon, a race along Extraterrestrial Highway this year on the weekend of August 16.

Towering to 14,411 feet, the snowy stratovolcano of Mount Rainier is among the most striking mountain peaks in the country. It's also the site of an incident involving Kenneth Arnold, a businessman s into the national lexicon.

For more information: National Park Service

© Stephen Alvarez

Chiapas, Mexico

The idiosyncratic iconography on an ancient tomb lid found at Palenque in the Mexican state of Chiapas has for decades cast speculation of the ancient Maya and their involvement with beings from out of this world. Dubbed the "Palenque Astronaut," the image shows a seated Mayan ruler in what some think is a space craft. Interpretations cite the cryptic carving as containing depictions of ignition and braking systems, a head rest, an engine and a oxygen nozzle pressed against the pilot's upturned nose.

For more information: Travel Chiapas

© Alejandro Balaguer/Getty Images

Nazca Lines, Peru

Noted as being "among archaeology's greatest enigmas" by the United Nations Educational Scientific and Cultural Organisation (UNESCO), the giant geoglyphs of Peru's Nazca Desert have long been seen as signs of either aliens or the gods above. Scratched on the ground about 2,000 years ago, the images of creatures, plants and geometric figures arc hundreds of feet across dirt and sand. They are nearly imperceptible on the ground, though take shape as objects of art when seen from an airplane... or a UFO.

For more information: Peru Gateway Travel