Codnor Castle is a ruined 13th-century fortress in Derbyshire, England, originally established by William Peverel following the Norman Conquest. The castle passed through the prestigious Grey and Zouch families before being sold to the Archbishop of York in the 17th century, eventually becoming abandoned by the late 1600s. The fragmentary remains preserve a three-storey keep, strong curtain walls, and round towers flanking deep defensive ditches, with archaeological evidence of medieval orchards and vineyards alongside later ornamental garden features. The ruins demonstrate medieval defensive engineering with clear evidence of 14th and 15th-century rebuilding, providing insight into feudal architectural evolution.