Brean Down Fort was built between December 1864 and July 1871 for a total cost of £12,623. The Battery mounted seven 7-inch RBL guns and provided part of the defence line stretching across to Lavernock Battery on the North side of the estuary. The battery included barrack accommodation and magazine and the land approach was protected by a dry ditch and loop holed wall.
In 1900 there was a magazine explosion and the following year the fortification was vacated. A new 6-inch battery was built on the site in World War 2.
Although called a fort, it was more of a coastal defence battery and has been classified thus.
Brean Down Fort was built to work in conjunction with the six batteries on Steep Holm Island that lay 3 miles off shore.