The world of The attack of the giants originally it consisted of an area surrounded by very high walls. Three circles of walls blocked mankind, preventing both men from going outside and giants from getting inside. Everything seemed closed, with an unreachable and unknown world.
However, things changed with the Battle of Shiganshina. It has been found that the outside world is in fact inhabited by other humans and that some of them, the Marleyans, turned the Eldians into giants in order to storm the walls and reclaim the power of the Nine Giants. Here we begin to better understand the conformation of the world of The Attack of the Giants, which in some ways is very similar to ours.
There is one detail in the manga in particular that makes the planisphere clearly understandable. How the world of Attack of the Giants is created? As you can see in the image below, Hajime Isayama basically decided to turn our world upside down on both axes. We therefore have Paradis in Madagascar and Marley in the southern region of Africa. The Arabian Peninsula and Europe can also be seen.
So the The world of The Attack of the Giants is geographically like oursthe only difference being the double tipping.