Buiyrandyn was a tiny drow settlement in the northern Underdark, beneath the northern Sword Mountains. It was also famous for rejecting Lolth and other evil drow deities. Besides that it was the birhtplace of Qilué Veladorn, one of the Seven Sisters. A long time before the 15th century DR, mindflayers destroyed it and since then it was occupied by evil monsters. It became the lair of a small clan of hook horrors.