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. 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.