Knowth is the name given to a number of passage graves, in the Boyne valley in Ireland. It consists of a bigger tumulus with two passages, and of 20 smaller ones. Of the smaller graves, 17 remain, 3 have been destroyed. Knowth is approximately 1 km west of Newgrange. It is probably older than Newgrange, which has been dated to about 3.150 BCE, but not as old as Dowth. The main tumulus is one of the biggest to be found in Ireland.