Souta's group secretly arrived in Buckshawn State. The living labyrinth was situated in this place. They cleaned up a part of the forest and camouflaged the floating fortress to make it look like a mountain.
Only a few people were left to guard it, and they didn't worry about people stealing it. The controls for the floating fortress were with Torkez, so no one would be able to control or move it. The original controls of the floating fortress were left to Jamine and Torkez, who simply created a duplicate controller to pilot the one that they brought.
The people that were left to guard it were Gyun's party, which Alice brought, and a few comrades of Torkez when he was fighting the empire decades ago. Eleven people were left inside the fortress, and they were training to improve their strength.
Souta even said that they could come out and explore the forest and fight some monsters to improve their experience in combat.