Nod y gefeillio yw ‒ hyrwyddo twristiaeth gynaliadwy ar y ddau safle; defnyddio prosiectau addysgiadol i hyrwyddo gwybodaeth am y cestyll, am eu hanes a'r cymunedau o'u hamgylch; a chyfnewid sgiliau ac arbenigedd drwy gynnal gweithgareddau diwylliannol a chwaraeon ar y cyd.
The aim of the twinning is to - promote sustainable tourism at both sites; use educational projects to promote knowledge about the castles, their histories and the communities around them; and to exchange skills and expertise through joint cultural and sporting activities.