Leiston Fortress is a military stronghold along the Lake Valleria shore in the province of Zeiss. Unlike many of the others, this one is the national headquarters of Liberl's Royal Army.

A large battalion of soldiers, led by Major Cid, guards the fortress. Within, they hold an armoury, barracks, research center, command center, landing port, a wharf and a watchtower. They also secretly hide the nation's worst criminals in the dungeon below the command center.

The fortress is said to be impenetrable, but don't tell that for those who have infiltrated it.