One of the significant concerns about the Erebonian Empire is the infamous Railway Gun (列車砲 Resshahou), one of the most devastating weapons built by the Reinford Group. Stationed within the Garrelia Fortress walls, It serves as an all-attempt means to thwart enemies approaching the Imperial border, and to conquer Crossbell State.
In the events of The Legend of Heroes: Ao no Kiseki, the weapon along with the entire fortress was decimated into hollow space by Ouroboros's Aion robots.