The Old Schoolhouse is a building that was built some time during the Dark Ages. It was originally used as Jenis' main school building until the school renovated itself and built a new campus in S.1182. It was then used as a hiding spot for students until it was locked up and finally abandoned when dangerous monsters snuck into the building in S.1202.
During the Ghost Incidents in Liberl, the building served as the main base for Enforcer No. X: Bleublanc and was abandoned once he had completed his experiments. Bleublanc also made use of the ruins underneath.