Post Office – Castle Douglas, Auchencairn – Opening Hours & Branch Details Post Office can be found in an ideal position on Main Street, approximately a 7.11 mile distance south from the centre of Castle Douglas (by Village). This branch provides service chiefly to the districts of Dundrennan, Scaur, Balcary, Rockcliffe, Bankhead, Palnackie and Auchencairn. Today (Friday), you can drop in 9:00 am to 1:00 pm. This page will supply you with all the information you need about Post Office Castle Douglas, Auchencairn, including the working times, address particulars, direct contact number and further significant details.