Board Thread:General Discussion/@comment-70.114.210.192-20160228123822/@comment-25936766-20170416123954

GreyStark wrote: There was something similar in Asoiaf, in it there's a castle called the Dunfort and dun means fort (some people think that that's where the "don" comes from in London) "Dun = Fort" is kind of restricted to Ireland and Scotland though.

Dun, in english, means "brownish grey", so "Dun Fort" could easily mean "Brownish Grey Fort". From what I saw of art of said fort, it's color is along those lines.

And while there's no 100% certainty, some etymologist theorize that it could have a common ancestry of some extent with the word Dusk, usually as: From Irish "Donn", from Proto-Celtic "Dunno-", from Proto-Indo-European "Donnos / Dusnos" (Dark).