The Forty Foot is a promontory on the southern tip of Dublin Bay at Sandycove, County Dublin, Ireland, from which people have been swimming in the Irish Sea all year round for some 250 years.
In former times it was exclusively a gentlemen's bathing place and the gentlemen's swimming club was established to help conserve the area. The gentlemen's swimming club still exists and is open to both genders, it expects voluntary contributions to the upkeep of the area.
There is no definite explanation for the origin of the name. It has been speculated that it may have been called the Forty Foot after the 42nd Highland Regiment of Foot (now known as the Black Watch), a regiment of the British Army, which is said to have been stationed here. Other suggestions forwarded include the depth of the water (actually less than 40 feet) and the width of the road leading to the bathing place