From
http://www.bermuda-online.org/forts.htm:
With 22 acres of fortified magnificent views, park land, picnic areas and walking trails. It was built in the 1860's and finished in the 1870's by the British Army's Royal Engineers, when the United Kingdom believed hawkish elements in the USA were conspiring to seize the Royal Naval Dockyard in retaliation for the role British ships played in helping the Confederate forces and using Bermuda as one of their ports. The fort protected the "land front" of the Dockyard from any enemy attack from South Shore beaches. An enormous dry moat was cut right across Somerset Island. Troops invading it from the mainland would have crossed under withering fire from cannons and rifles. As an inland fort, Fort Scaur had small 64 pound guns on disappearing carriages.