River Lapendrar

The River Lapendrar (or the River of Sorrows) is a river that, as of 1357 DR, formed the western boundary of Thay, in East Faerûn. It is named "River of Sorrows" after the gold miners who died working its banks and the Aglarondan army who died there.

Battle of Lapendrar
In 1260 DR, an Aglarondan army led by Halacar invades Thay, and is defeated by the Red Wizards.