First Mentioned: LIAB Prologue 13
It is located near the site of the former capital of Unaroyal.
The city may have been razed and rebuilt under another name after being captured by Gobwin Knob.
Real World References
"Unabrow" seems to be related to "unibrow" which is a slang reference to a person's eyebrows which have grown together, making the appearance of having only one eyebrow that spans the entire face, above both eyebrows.