Marthenshire is a shire of Somery. The shire is made up of the heartland of lathe Mar. Most of the population can be found in the Mar and Dwill valleys. The area is quite hilly, especially in the east where the Rimn Hills dominate. The shire has one of the most dramatic shorelines in the country, and the Lancreigh Shoreline National Park Trail between Twillingham and Perwyn, in Campshire, offers a walk with unforgettable and breathtaking sights.