The Obsidian Citadel is situated on an island, separated from the mainland and has a rigid security system that does not allow a single intruder to enter the piece of land without alerting the authorities.
Not only was the academy situated on the island, but every other necessity of a student was made available for them, leaving no requirement to leave the island unless any dire situation arose.
Ethan has only heard about this place in the past, but not even once he thought he would get the opportunity to enrol here—on a fully-funded scholarship, no less.
It was something related to that awakening he went through in Awsperg that made the administration of the Academy interested in him—Ethen thought.