Morentwyshire is a shire of Somery. The shire covers about two thirds of the old lathe Shirleith, of which Morentwy was the capital. A great deal of the population is concentrated to the lower parts of the Eddin and Entwy valleys. The far south is dominated by the wide moors of Branmoor Hills. Shereddin Wetlands National Park is a marshland bird reserve centred at the estuary of the river Eddin. Parts of the wetlands have been drained and cultivated, with a network of canals. The Dunes in the northeast form a coastal lowland with long beaches.