Wat's Dyke is a 40-mile linear earthwork running through the northern Welsh Marches from Basingwerk Abbey on the River Dee estuary, passing east of Oswestry and on to Maesbury in Shropshire, England.

Offa's Dyke is a large linear earthwork that roughly follows the border between England and Wales. The structure is named after Offa, the Anglo-Saxon king of Mercia from 757 to 796 CE, who is traditio