Why attack on titan?

It is a dark fantasy anime that captivates anime fans with its interesting concept. It was adapted from the manga Attack on Titan, and the manga was released in April 2013.
It is set in a world where humanity lives inside cities surrounded by three enormous walls that protect them from the gigantic man-eating humanoids referred to as Titans.

What are the titans?

Titans were a species of giant, man-eating humanoids that served as the catalyst for the events in the Attack on Titan series. Most titans showed no signs of intelligence and acted like mindless beasts-easy to trick, distract, and deceive.

Where does the story takes place?

Attack on Titan takes place in a parallel universe that is very much like ours geographically and somewhaat culturally similar. The events take place mainly on Paradis Island.
All of them happen in paradis island where the fritz king fled with the other elidan people ( not all of them.) Half of elidans were led with Marleyans). All these titans were originally Eldian people who were transformed into mindless titans as a punishment by marleyans. They ship them to the paradis island and change them.