Now conspiracy theorists claim to have found evidence of an alien base on Smyley Island, off the west coast of the Antarctic Peninsula, on Google maps.
They believe this peculiar object, around 500-metres long, near the Antarctic could be an underwater alien base.
Theories about secret bases in the Antarctic have circulated for years – with one conspiracy detailing that the Nazis had secret bases in the southernmost continent which they used to experiment on captured UFOs during WWII.
The new object was spotted on Google maps by website UFO Sightings Hotspot which has revealed its “findings”.
The unusual object has been described as a “large body of ice sheered off of the side of the continent”.
Many people have reacted to say that it is just an iceberg, but UFO hunters say its strange shape rules the suggestion out.
The website says it does not fit with the normal shapes of usual categories of iceberg.
It said: “Icebergs can be classified on the basis of their shape.
“The two basic types of iceberg forms are tabular and non-tabular.
“The shapes and forms from this iceberg look very different if we compare it with all the different shapes and forms of tabular and non-tabular icebergs.”
The website added: “I’m not an iceberg expert but this object is really peculiar and looks like a vessel disguised as an iceberg.
“It looks out of place.”
But UFO sceptic Scott Brando said: “I don’t see any mystery, it just looks like ice.”
Another bizarre Antarctic claim is that John Kerry visited the alleged site of the secret Nazi UFO base.