The river's source is next to Craft Lane, close to Furyhill plantation between Northrepps and the hamlet of Frogshall.

It runs in a southeasterly direction through a wooded valley and passes under Craft Lane close to Frogshall Farm House.

Bream, carp, tench and roach can be caught.In the lake, pit and river, From Gimingham the river cross more open farm land now heading east, passing on its left Mundesley Hospital which was refurbished in 1997 and is now the Diana Princess of Wales Treatment Centre for Drug and Alcohol Problems.

Where the road leading up to the hospital crosses the River Mun, the Environment Agency has a Water Resource Management gauging station.

The golf club was established in 1901, and was designed with the help of one of the sport's legends, 6-times Open winner Harry Vardon (1870–1937), built on the rolling hillside of the River Mun valley.

Just past Trunch Road the river falls over another weir before turning north into the eastern side of the village.

The only way to provide a sufficient head of water was to dam the river to form the mill pond we see today which is some considerable height above the road.

When the mill was worked by the Larter family in the 1920s, the deeds stated that anyone interfering with the river had to pay dues to the millers.

The waterwheel was large with a diameter of 26 feet (7.9 m) and the owner of the Mill House decided to enclose the wheel behind a grill and to leave it as a showpiece.