Post Office – Llanon, Cross Inn – Opening Hours & Branch Details Post Office is currently found on Glanarthen Stores, approximately 2.49 miles south-east from the centre of Llanon (near Cross Inn). This branch is an important addition to the locales of Penuwch, Llansantffraid, Ciliau-Aeron, Nebo, Cilcennin and Cross Inn. Its hours of opening are 9:00 am – 12:00 pm today (Friday). Refer to this page for information about Post Office Llanon, Cross Inn, including the open hours, branch address info, direct phone and more.