Hey, My name's Wight on Steam and I have some ideas for extinct/in exile houses and their castles.
House Fisher: Deposed as kings of the Riverlands. Mudds succeeded them so I'd guess that they are still around in some way, shape or form.
-Misty Isle: The Castle of House Fisher. The exact location is unknown but i'd put it either near Riverrun or Oldstones but definitely in one of the three forks as it's called an isle. Maybe a prestige bonus and a fort level or two as it was the capital of an old royal dynasty. Made out of stone up river and sent downstream.
House Hook: Kings of the Riverlands who claimed the mouth of Blackwater Rush. Unknown as to whether they are First Men or Andals.
-Unknown Castle name: Castle of House Hook. Location is really unknown but I'd probably put them somewhere along Blackwater Rush and it's tributaries. Same bonus as house Fisher. Made out of stone near Blackwater Rush (or it's tributaries) and sent downstream.
House Brightstone: Kings of the Fingers. Jon Brightstone was killed by a Corbray and had his daughter taken as his wife. Probably a son or three left.
-Unknown castle name: Castle of house Brightstone. Somewhere in the fingers. Maybe a tax income bonus from fishing or mining. The name Brightstone suggests ore and gems of value. Made out of stone from quarries near said mine(s).
House Nutt: Lords in the Riverlands. Lady Jeyne Nutt lead a rebellion later in the timeline so they're either an Andal house or a First Men house. an either have them be a Barony or be part of the Andal Horde. Simplistic name seems to suggest it being a First Men house.
House Shell: Kings of the Fingers. At war with house Brightstone. King Dywen Shell paid Corwyn Corbray (as did Jon Brightstone) to kill his rival but Corwyn betrayed them both and took his daughter as his bedwarmer. As with House Brightstone there are likely other members of his family still alive.
-Unknown castle name: Castle of house Shell. A burnt down wooden longhouse so unimportant really. Likely on another one of the fingers. Bonus could be anything.
House Ryder: Kings of the Rills. Subdued by Starks but don't know when.
-Unknown castle name: Castle of House Ryder. Could be the castle of the Ryswells by ACOK? Likely either next to one of the lakes or near some of the hills/mountains. Depending on where it is you could have it get tax income from fishing or mining and a construction speed bonus from mining. Likely made out of stone from mines.
House Briar: High Kings of Dorne. One of twenty First Men lords of the Greenblood. Destroyed during Andal Invasion.
-Unknown castle name: Castle of house Briar. Situated on the Greenblood. As briars are bushes it could be a nice habitable place in Dorne. Maybe a tax income bonus from extra people/the Greenblood itself. Likely made of stone from further up the Greenblood that's sent down.
House Brook: High Kings of Dorne. Basically like house Briar.
-Unknown castle name: Castle of house Brook. Situated on the Greenblood. Brooks are small rivers/streams so a tax income bonus from having a nice source of water in a desert. Made of stone from further upstream.
House Brownhill: High Kings of Dorne. See above
-Unknown castle name: Castle of house Brownhill. On the Greenblood and likely on a hill. Fort level bonus. Made of stone from nearby hills.
House Holt: See above.
House Hill: See above.
House Lake: See above.
House Shell: See above.
House Wade: See above.
House Woodfoot: Rulers of Bear island. Were "vanquished" by the ironborn in Theon "Hungry Wolf" Stark's reign. Depending on your start date you could have them either as lords/barons of Bear Island or as an exiled house.
-Woodfoot Watch: Probably not that big. Maybe as big as Mormont Keep. In Bear Island so it's probably a wooden keep with a stone base. Bonus fort level and either bonus men (because they let women fight) or a tax modifier because of fishing in the Bay of Ice.
House Fisher: Deposed as kings of the Riverlands. Mudds succeeded them so I'd guess that they are still around in some way, shape or form.
-Misty Isle: The Castle of House Fisher. The exact location is unknown but i'd put it either near Riverrun or Oldstones but definitely in one of the three forks as it's called an isle. Maybe a prestige bonus and a fort level or two as it was the capital of an old royal dynasty. Made out of stone up river and sent downstream.
House Hook: Kings of the Riverlands who claimed the mouth of Blackwater Rush. Unknown as to whether they are First Men or Andals.
-Unknown Castle name: Castle of House Hook. Location is really unknown but I'd probably put them somewhere along Blackwater Rush and it's tributaries. Same bonus as house Fisher. Made out of stone near Blackwater Rush (or it's tributaries) and sent downstream.
House Brightstone: Kings of the Fingers. Jon Brightstone was killed by a Corbray and had his daughter taken as his wife. Probably a son or three left.
-Unknown castle name: Castle of house Brightstone. Somewhere in the fingers. Maybe a tax income bonus from fishing or mining. The name Brightstone suggests ore and gems of value. Made out of stone from quarries near said mine(s).
House Nutt: Lords in the Riverlands. Lady Jeyne Nutt lead a rebellion later in the timeline so they're either an Andal house or a First Men house. an either have them be a Barony or be part of the Andal Horde. Simplistic name seems to suggest it being a First Men house.
House Shell: Kings of the Fingers. At war with house Brightstone. King Dywen Shell paid Corwyn Corbray (as did Jon Brightstone) to kill his rival but Corwyn betrayed them both and took his daughter as his bedwarmer. As with House Brightstone there are likely other members of his family still alive.
-Unknown castle name: Castle of house Shell. A burnt down wooden longhouse so unimportant really. Likely on another one of the fingers. Bonus could be anything.
House Ryder: Kings of the Rills. Subdued by Starks but don't know when.
-Unknown castle name: Castle of House Ryder. Could be the castle of the Ryswells by ACOK? Likely either next to one of the lakes or near some of the hills/mountains. Depending on where it is you could have it get tax income from fishing or mining and a construction speed bonus from mining. Likely made out of stone from mines.
House Briar: High Kings of Dorne. One of twenty First Men lords of the Greenblood. Destroyed during Andal Invasion.
-Unknown castle name: Castle of house Briar. Situated on the Greenblood. As briars are bushes it could be a nice habitable place in Dorne. Maybe a tax income bonus from extra people/the Greenblood itself. Likely made of stone from further up the Greenblood that's sent down.
House Brook: High Kings of Dorne. Basically like house Briar.
-Unknown castle name: Castle of house Brook. Situated on the Greenblood. Brooks are small rivers/streams so a tax income bonus from having a nice source of water in a desert. Made of stone from further upstream.
House Brownhill: High Kings of Dorne. See above
-Unknown castle name: Castle of house Brownhill. On the Greenblood and likely on a hill. Fort level bonus. Made of stone from nearby hills.
House Holt: See above.
House Hill: See above.
House Lake: See above.
House Shell: See above.
House Wade: See above.
House Woodfoot: Rulers of Bear island. Were "vanquished" by the ironborn in Theon "Hungry Wolf" Stark's reign. Depending on your start date you could have them either as lords/barons of Bear Island or as an exiled house.
-Woodfoot Watch: Probably not that big. Maybe as big as Mormont Keep. In Bear Island so it's probably a wooden keep with a stone base. Bonus fort level and either bonus men (because they let women fight) or a tax modifier because of fishing in the Bay of Ice.