Post Office – Castlewellan – Opening Hours & Branch Details Post Office is directly positioned at 71 Main Street, approximately a 0.08 mile drive south-west of the centre of Castlewellan (by Castlewellan Forest Park and Saint Malachy’s Church). This branch provides service chiefly to the districts of Castlewellan Peace Maze, Clarkill, Burrenreagh, Dundrinne, Newcastle, Annsborough and Castlewellan Town Centre. Business times for today (Friday) are 9:00 am to 6:00 pm. This page will supply you with all the information you need about Post Office Castlewellan, including the working hours, street address, direct contact number and further significant details.