What is Offa's Dyke?
[[File:Mercian Supremacy x 4 alt.png|thumb|The extent of Mercia during the [[Mercian Supremacy]], showing the line of Offa's Dyke (red)]] [[File:Offa's Dyke cross-section colour.svg|thumb|Schematic cross-section of Offa's Dyke, showing the design intended to protect Mercia against attacks/raids from Powys.]] [[File:Offa's Dyke near Yew Tree Farm - geograph.org.uk - 450420.jpg|thumb|Offa's Dyke near [[Presteigne]] in the [[Welsh Marches]]]] '''Offa's Dyke''' ([[Welsh language|Welsh]]: ''Clawdd Offa'') is a large [[wikt:earthwork|earthwork]] that roughly follows the current border between [[England]] and [[Wales]]. The structure is named after [[Offa]], the [[8th century]] king of [[Mercia]]. He is believed to have ordered its construction. Its original purpose is not known for sure. It followed the border between [[Angles|Anglian]] Mercia and the Welsh kingdom of [[Powys]]. The dyke was up to 65 feet (20 m) wide (including its flanking ditch) and 8 feet (2.4 m) high. It ran over low ground, hills and rivers. Today the earthwork is protected as a [[scheduled monument]]. '''Offa's Dyke Path''' is a 177 mile (283 km) footpath which runs between [[Prestatyn]] in the north ([[Liverpool Bay]]) and [[Sedbury]], near [[Chepstow]] (the [[River Severn|Severn]] [[Estuary]]) in the south. This is from north of Offa's Dyke to south of it, and runs near the dyke in its central part. It is also thought to be constructed under the orders of Offa. It is a British [[National Trail]]. Some sections of the dyke are defined as [[Sites of Special Scientific Interest]], and [[Areas of Outstanding Natural Beauty]]. Most of the line of Offa's Dyke is designated as a [[Rights of way in England and Wales|Public Right of Way]], including those sections which form part of the Offa's Dyke Path.<ref name=heritage> UK Tentative List of Potential Sites for World Heritage Nomination: Application form: Offa's Dyke, Department for Culture, Media and Sport. [https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/78278/WHAF_O