Glad to inform people--- the passes have been available for quite a while and it was only by chance that my OH spotted something in the paper about them. We got our form from the desk at Conwy Castle-- not the TIC, they don't have them. Since we got the passes we have been to a number of CADW properties. Rhuddlan Castle was one of them, it is a dog friendly property too and one even gets a free poo bag at the gate ! "Wow !