| Castle Qua | |
| Type: | Prehistoric fort |
| Location: | Cartland Craigs Lanark South Lanarkshire United Kingdom |
| Designation1: | Scheduled monument |
| Designation1 Offname: | Castle Qua,fort 345m WSW of Mouse Bridge |
| Designation1 Date: | 18 July 1967 |
| Designation1 Number: | SM2604 |
Castle Qua (also known as Castle Quaw or Castle-dykes) is the name given to an earthwork found in the Cartland Craigs National Nature Reserve near Lanark, South Lanarkshire. It is site number NS84SE 1 in the records of the Royal Commission on the Ancient and Historical Monuments of Scotland. It's believed to be a medieval structure.[1]