Ahch-To was a planet mostly covered in water, with numerous rocky islands blanketed with green trees located in the Unknown Regions. It was the birthplace of the Jedi Order and held the ancient Jedi texts.

Do you know what happened to him? There’re a lot of rumours. Stories. The people who knew him the best thing he went looking for the first Jedi temple.

– Finn and Han Solo, on the whereabouts of Luke Skywalker

Three decades after the Galactic Civil War, it served as the home of Jedi Master Luke Skywalker who went into exile seeking the first Jedi Temple after his Jedi students were killed by Kylo Ren. After the Resistance pieced together two map fragments to reveal Skywalker’s location, Rey travelled to Ahch-To in the Millennium Falcon accompanied by R2-D2 and Chewbacca, in search of him.