Red Tarn is the highest altitude piece of water in England to contain fish. Brown trout appear to thrive in the place. But mysteriously considering the altitude and elevation, it also contains Britain's rarest fish the schelly. Protected under The Wildlife and Countryside Act, it is illegal to deliberately catch or harm this fish. But it wasn't when the archive section of this film was shot in the 1970's. This has been linked to more up to date footage of the trek to the top and the brown trout fishing.