Post Office – Llanon – Opening Hours & Branch Details Post Office can be found in an ideal spot on Llanon Spar, 0.03 miles south-west from the centre of Llanon (by Central Hotel). The branch is an added feature to the areas of Ffos-Y-Ffin, Llansantffraid, Cross Inn, Gilfachrheda, Llannon and Cilcennin. Today (Friday), service starts at 9:00 am and ends at 5:30 pm. This page will provide you with all the information you need on Post Office Llanon, including the operating times, directions, phone number and more info.