Dwarven Vaults

A dwarven vault may not be built in the civilized or borderland area of a human or elven realm, only in a dwarven realm, or wilderness area. Additionally, a dwarven vault must be an underground structure. While it may include above-ground gates, walls, or structures as necessary for defense or commerce, these cannot constitutre more than 25% of the gp value of the stronghold. Any above-ground structures must be of earth or stone. 
Dwarves usually live in clans, so dwarves of the vault builder's clan will be the first ot live under their roof, but dwarves from other clans will come and live nearby to be ruled by the character. A total of 3d6x10 1st level NPCs of the same race will move in to help maintain and defend the vault at no cost to the character. If additional defenders are needed, a dwarven ruler is expected to employ only soldiers of dwarven descent. They may hire members of other races for other tasks. 
Dwarven vaults are otherwise maintained like human domains.

Source: Adventurer, Conquerer, Kings System