Althier, formerly Brockhall, was the ancestral home of the Brock family, located in northeastern Mossflower Woods. It was once used as a meeting place and refuge for the Corim. It included small sitting rooms, a small infirmary, a nursery, a study, a master bedroom, dormitories, a kitchen, a larder, storerooms and a large main hall. Brockhall was most likely named for Lady Sable Brock.
Later, the Sable Quean Vilaya commandeered Brockhall and called the place Althier, an anagram for "The Lair". Only a few trusted guards, jailers Thwip and Binta, Zwilt the Shade, and Vilaya's loyal counselor Dirva ever knew its location.
Althier appears in The Sable Quean in canon.