I hope I've got the grid reference right. The barrows were behind North Foreland Lodge (later St Stephen's College, and now?).
Between Broadstairs and King's Gate there is a lighthouse, erected, in 1683, on the North Foreland, the most easterly point in England*[..] A desperate battle is said to have been fought by the Saxons and Danes near this place in 853, the site of which is marked by two tumuli.
From p 442 of 'The British Gazetteer' by Benjamin Clarke (v1, 1852). Spotted online at Google Books.
*Not actually true. The bit about the battle might not be actually either.