Post Office – Castle Douglas – Opening Hours & Branch Details You may visit Post Office at 100 King Street, approximately a 0.09 mile drive north-east of the centre of Castle Douglas (close to Market Hill and Academy Street). The branch is proud to provide service to customers within the areas of Townhead of Greenlaw, Bridge of Dee, Eriff, Gelston, Castle Douglas Town Centre, Kelton and Old Bridge of Urr. Its hours of opening for today (Friday) are 9:00 am until 5:30 pm. Refer to this page for the specifics on Post Office Castle Douglas, including the open hours, branch address details, customer reviews and more beneficial information.