The Caldicot and Wentloog Levels are two areas of low-lying estuarine alluvial wetland and intertidal mudflats adjoining the north bank of the Severn Estuary, either side of the River Usk estuary near Newport in south east Wales. They are also known collectively as the Monmouthshire Levels or Gwent Levels, and the name Wentloog is sometimes spelled Wentlooge in official publications. The Caldicot Level lies to the southeast of Newport between the River Usk and River Wye and consists of . It is home to Newport Wetlands Reserve. The Wentloog Level lies to the southwest between the River Usk and Rhymney River and consists of . The levels are formed from tidal deposits and alluvium, which have been recurrently inundated and reclaimed from the Severn Estuary by humans since Roman times. They have been patterns of settlement, enclosure and drainage systems belonging to successive periods of use, and are extremely rich archaeologically, with finds from the Mesolithic, Bronze Age and Iron Age periods. They are an important wetland resource. Parts have been designated as Sites of Special Scientific Interest. They are registered as a Historic Landscape of Outstanding Historic Interest in Wales. History and archaeology There have been variations in both land and sea levels in the Severn Estuary since the start of human habitation in the area. The Levels have been reclaimed from the sea at different times during the historic period, preserving evidence of patterns of settlement, enclosure and drainage systems. Mesolithic and later remains have been discovered at Goldcliff, and late Mesolithic human footprints at Uskmouth. One of the most significant finds was of a 3rd-century Romano-British boat found at Wilcrick near Magor. The Romans occupied the area from the 2nd to the 4th centuries. In 1878, a boundary stone marking the building of 33 paces of embankment by Roman soldiers was discovered at Goldcliff. Research suggests that, initially, reclamation of the natural salt marsh for farmland began at a few "island" sites within the marshes, such as at Nash and Redwick, before a sea wall was built along the whole coast. Goldcliff Priory was established in 1113 and together with other major landowners took responsibility for further drainage work in the area. Settlements became established, linked by droveways such as the Whitewall at Magor, and land was gradually reclaimed for pasture and arable use. A large number of Anglo-Norman sites including castles, churches, court houses, manor houses,