The first monolith was found in the desert in the state of Utah in the USA.
Since then, they have been found all over the world.
In Sweden in Katrineholm and in the Jönköping area.
A monolith is a larger object made of a single piece of material, such as stone, according to the National Encyclopedia.
The Gotland thus falls a little out of bounds because it is welded together by rusty plates, according to the news site.
See pictures of the monolith in the video above.