Mori'tarna is a tunnel network in Underdark under Silver Shore Island. This territory is ruled by Great Matron Council of Silver Shore and The Great Mothers. It is relatively separate of the rest of the Underdark tunnel network and well defensible, connecting to Scar Deep Roads.It used to be part of the network of Szith Draethoz, before breaking away from it during the time of The Cracking.
The area is mainly accessible only through Scar Deep Roads and through surface passage close to the in the Great Forest. Network has several large caverns, some of them filled with small Drow villages, with two big cities; Netehdrez and Zaetron Derraz. Currently, only reliable way to reach Zaetron Derraz is going through Netehdrez.