The spherical stone which was discovered last month in the Podubravlje forest in Bosnia is puzzling the scientific community.
The half-buried stone was found by Bosnian archaeologist Sam Osmanagich.
According to estimates, it weighs about 30 tons and measures up to 1.5 metres in diameter. Its brown-reddish colour suggests it is partly composed of iron, but analysis has yet to be done.
Are these alien artifacts?