Ramsey Hairpin (Manx: Ballacowle – Cowle's farm) is situated between the 24th Milestone and 25th Milestone road-side markers on the Snaefell Mountain Course used for the Isle of Man TT Races on the A18 Snaefell Mountain Road in the parish of Lezayre in the Isle of Man.
The A18 Snaefell Mountain Road was developed in the mid-nineteenth century from a number of pre-existing tracks and bridle paths. As this section of the A18 Mountain Road is purpose built from Whitegates to the Gooseneck, it reflects typical nineteenth highway and railway construction practices including the building of a purpose built Hairpin turn at Ballacowle Glen on the outskirts of the town of Ramsey. The Ballacowle Glen later renamed Elfin Glen to attract tourist was purchased by the Isle of Man Forestry, Lands and Mines Board in 1963 along with the nearby Lhergy Frissel and Claughbane Woods. The combined glens including a disused slate quarry, cover an area of 64 acres (260,000 m2) on steeply sided mountain-side slopes with many different species of Deciduous and Coniferous trees.
The Ramsey Hairpin was part of the Highland Course and the Four Inch Course used for the Gordon Bennett Trial and Tourist Trophy automobile car races held in the Isle of Man between 1904 and 1922. The Ramsey Hairpin is now part of the Snaefell Mountain Course used since 1911 for the Isle of Man TT and 1923 for the Manx Grand Prix Races.