Drammankin Lake
The Lake of Mutations, formerly known as Drammakin Lake, was a body of water on Skaro located near a mountain range. It was home to monstrous mutations created by the use of chemical-biological weapons during the Thousand Day War.
Nasgard's family lived in a villa by the lakeside for generations. During his childhood, Davros spent much of his time sitting by the lake, as he was fascinated by the creatures living in it. (BFD: Innocence)
Years later, the Dalek City was built near the mountain range bordering the now-polluted Lake. Giant pipes went directly through the mountains to the Lake for the City's water supply. (DW: The Daleks) The Daleks also kept their anti-missile rockets beneath the waters of the Lake. (DC: Impasse, The Terrorkon Harvest)
A Terrorkon, one of the creatures living in the Lake, attacked a Dalek station, but was itself attacked and killed by an giant eel-like creature. (DC: The Terrorkon Harvest)
Three members of the Thal party led by Temmosus were killed by creatures in the Lake when they first discovered it. Ian Chesterton led a second trip around the Lake to sneak into the City, during which another Thal, Elyon, was killed by one of the creatures. (DW: The Daleks)