The Thondroril River forms a natural boundary between the Western and Eastern Plaguelands. The spring of this river is located in the current closed area known as Northern Lordaeron and runs from near the Terrorweb Tunnel to the north and empties out into Darrowmere Lake to the south, although the river that runs from Darrowmere Lake and empties out into the ocean at Southshore can also be called Thondroril river, as it is an extension of it.