Cadzow Castle, now in ruins, was constructed between 1500 and 1550 at a site one mile south-east of the centre of Hamilton, South Lanarkshire, Scotland. The earlier medieval settlement of Hamilton was formerly known as Cadzow or Cadyou[1] (Middle Scots: Cadȝow), until it was renamed in 1455 in honour of James Hamilton, 1st Lord Hamilton.[2] The castle sits above a gorge overlooking the Avon Water in what is now Chatelherault Country Park, but was previously the hunting and pleasure grounds of the duke of Hamilton's estate of Hamilton Palace - this area being known as Hamilton High Parks. The ruin is a Scheduled Ancient Monument.[3]