Quotes of the Day

If mankind is visiting Mars, why not the reverse? Maybe signs of life are hard to come by up there because all the Martians are down here. And maybe not. But here are the top destinations for the discerning Martian hunter.

ROSWELL: As every UFO enthusiast knows, an alien spacecraft putatively crashed in the desert near this New Mexico town in 1947—and the U.S. military tried to cover it up. At the Roswell International UFO Museum, visitors can examine hundreds of autopsy drawings, sworn affidavits and newspaper reports from the time of the crash. And pick up a tasty Alien Cookie Kit in the gift shop for $7.95.

AVEBURY: For two decades, the fields surrounding this English village have become a hot spot for crop circles (above)—said to be crafted (at night, presumably) by artistic visitors from another planet. Added bonus: Stonehenge is under an hour away.

BONNYBRIDGE: If it's a close encounter you're after, go to the UFO capital of the world. Over the past decade there have been an incredible—some might say unlikely—60,000 UFO sightings in and around this small Scottish town. That's 10 for each resident.

HAKUI: This Japanese city's space center, Cosmo Isle Hakui, provides a very grounded examination of extraterrestrial life. The museum boasts an in-depth exhibition about the SETI project, which aims to discover intelligent alien life, as well as space artifacts like a prototype Moon buggy.

INTERLAKEN: Founded by UFO expert Erich von Däniken, Mystery Park in Switzerland explores, among other things, possible contact between aliens and ancient civilizations like the Maya.

• Theunis Bates
• Get into the swing of all things extraterrestrial at the world's most-visited "visited" sites