Post Office – Penzance, Sennen And Lands End – Opening Hours & Branch Details You can visit Post Office on Mayon, approximately 7.68 miles south-west of the centre of Penzance (close to First And Last Inn). This branch principally serves the people in the locales of Lower Bosistow, Trevedra Common, Treeve Common, Mayon, Greeb Farm, Lion’s Den, Sennen and Sennen Cove. Today’s (Friday) hours of operation are 8:00 am – 8:00 pm. Read the specifics on this page for Post Office Penzance, Sennen And Lands End, including the business hours, address, telephone details and more.