In 2012, a survey by the National Geographic found that 77% of the Americans believe that intelligent beings outside our planet not only exist, but also already come into contact with human beings. Disclaimer: this article may be sympathetic to the belief of alien visitation, but it does not boldly claim that sapient extraterrestrial beings actually exist, let alone live among humanity. All of the top 5 alien sites on earth just seem too strange to comprehend.
Nazca Desert, Peru
In the vast desert of Peru, several centuries old geoglyphs marked the terrain depicting recognizable images. Among them include a spider, a monkey, a dwarfish human, and a hummingbird - all of which drawn on land at an immense scale only visible from bird's eye view. Arguably, the most misunderstood of the images is the 'anachronistic' airplane landing pad stretching a distance of several miles.
Easter Island, Chile
The flat and elongated faces of the Moai statues located in Chile's Easter Island continue to baffle visitors. Each one of these colossal stone heads erected firmly on the ground proved an unsolved (definitively) engineering puzzle - leaving the average people to speculate on 'ancient alien' knowledge being responsible.
It is not so much as the engineering marvel which made the Great Pyramids and the Sphinx a subject of 'ancient alien' speculation, but rather the curious placement of the structures. The coordinates of these monuments not only map the Orion constellation, mathematicians even decode a sophisticated calendar counting 50,000 years per segment.
The ruins of Puma Punku continue to baffle even the advanced engineers of contemporary times. With each stone weighing about 800 tons, it is plausible to question how most of these stone blocks resemble a level of stone carving theoretically achievable with powered precision tools - while these ruins were built centuries ago.
If there is any other place on earth that seems to suggest alien existence on earth, it is the infamous Area 51 in Nevada. This classified US Air Force facility is believed to be an asylum for extraterrestrials in our present time. Although the nearest town attracts visitors, the armed soldiers stationed at the base are authorized to use deadly force against intruders.