If you have a local BT57 address then you can obtain a FREE car-park pass by taking a domestic bill to the National Trust
I've not been able to find details of this free pass on the NT website; perhaps it will be added next time the site is updated.
The Giants Causeway and Carrickarede Rope Bridge are just two of the highlights
of the Baronies of Cary and Upper and Lower Dunluce in the north of County Antrim.