Cassandra Clare said this quote

The Scholomance was a piece of Shadowhunter history come to life. A cold castle of towers and corridors carved into the side of a mountain in the Carpathians, it had existed for centuries as a place where the most elite of Shadowhunters were trained to deal with the double menaces of demons and Downworlders. It had been closed when the first Accords were signed: a show of faith that Downworlders and Shadowhunters were no longer at war.