Map showing the area around FCD#3 and the tunnels under the White house.
Frigid River was the greatest river of the Great Underground Empire, over 150 bloits long. It is surrounnded by towering white cliffs. Rocks poke through the surface of the river, causing rapids.
It was formed at the spilloff of the Reservoir from the Flood Control Dam #3, then through a gaping cave opening it flows outside, pours over Aragain Falls, reaches the Frigid River Valley, its runoff basin, and at its southern end it empties into the Great Sea.