the transient traders park all over there on a regular basis and as eirbus said the MPs and curragh rangers will move you , that said the Mps have no jurisdiction on the curragh racecourse side of the motorway but the ranger is there mostly during working hours so there is places you could ALLE without too much hassle and the MPs wouldnt be too bothered as long as you stay away from the camp and range area other than that you would be fine.