Fen of Serech.

Marches of Serech.

Infront of the pass to the Narrow Land and Beleriand in the South-Western corner of Anfauglith is the Marshes of Serech. Though Ard-Galen had become a wasteland the river Sirion from Ered Wethrin, and its tributary Rivil from Dorthonion, meet eachother infront of the gap of the Narrow Land held enough water to create a large area with marshes and moors.