The River Slang, also known as the Dundrum Slang or the Dundrum River, a tributary of the River Dodder, is a stream which rises on Three Rock Mountain, County Dublin. It is in the local government area of Dún Laoghaire–Rathdown.

Milltown is a suburb on the southside of Dublin, Ireland. Milltown was the site of several working mills on the River Dodder and is also the location of the meeting of the River Slang with the Dodder. It is located adjacent to other suburban areas such as Windy Arbour, Ranelagh, Rathmines, Dartry, Clonskeagh, and Donnybrook.