Something like  the Lanisters or Tyrell i suppose. A house of riches and pride. I envision their territory containing many mountains and mines and that metals and minerals are their major exports. Silver and Iron being the most abundant. The family keep I picture being literally built from a mountain, perhaps carved down into shape from the time when the family first formed and began to mine the area. Deep beneath the keep I picture there being a bit of carefully contained ( via magic of course ) lava, suggesting that the mountain castle was once a volcano. They use the primal source of heat to fuel the fires of the Great Forge, which processes a lions share of metals they mine.