Quarterbridge (Manx: The Quarters or Quarter Dub – quarterlands of Ballabrooie and Ballaquayle) is situated between the 1st Milestone and 2nd Milestone road-side marker on the Snaefell Mountain Course used for the Isle of Man TT Races on the junction of the primary A1 Douglas to Peel road, A2 Douglas to Ramsey Road and the A5 Douglas to Port Erin Road which forms the boundary between the parishes of Braddan and Onchan in the Isle of Man.