Hi Fivid,
Diamond Head, Kylies etc. are in the National Park so no dogs allowed, but Coopernook State Forest 30klms. south of
Kew is a free camp and dog friendly. It is 20klms. from Harrington where there are dog friendly beaches.
There is an article about Coopernook S.F. at traveldogsaustralia.com/coopernook. No showers, flush toilet and bring your own water, have driven past and it`s a really nice area.
There is also the Colonial Leisure Village on the way into Harrington, mainly residential but has a pet friendly camping area and it wasn`t busy last Christmas. Hasn`t got all the bells and whistles that the Big4 in Harrington has.
Cheers, Robyn.