Post Office – Newcastle, Donard – Opening Hours & Branch Details Post Office occupies an ideal site at 6 Railway Street, a 178.89 mile driving distance west from the centre of Newcastle (near Royal County Down Golf Course and The Church of St Mary of The Assumption). The branch essentially serves the customers in the areas of Ballynahinch, Castlewellan, Downpatrick, Newcastle Town Centre, Murlough Upper, Ballaghbeg and Tollymore. Doors are open today (Friday) from 9:00 am until 5:30 pm. This page will provide you with all the information you need on Post Office Newcastle, Donard, including the working hours, location particulars, customer experience and other beneficial info.