Guisachan Fall is a waterfall in the Highlands of Scotland, south of Glen Affric. It is located in Srath Allt na Sìdean about 2.5 km (1.6 mi) south west of the village of Tomich, in The waterfall is formed by the Allt na Sìdean, a right-bank tributary of the Abhainn Deabhag, which in turn is a right-bank tributary of the River Affric. The waterfall is variously claimed to be about 80 to 90 feet high, and is located at an altitude of about 130 m (430 ft) above sea level.