The castle was built in the 15th century by Ralph, 3rd Lord Cromwell, Lord Treasurer of England, on the site of a previous 13th century castle. The centerpiece of the surviving ruins is the 110 foot tall red-brick medieval keep tower.
The castle was left to the National Trust by Lord Curzon of Kedleston on his death.
The steamer was built in 1934 as a passenger ferry on the Humber estuary between Kingston-upon-Hull and New Holland. It was used as a tethering boat for barrage balloons during the Second World War. In 1975 the boat was towed to London after the errection of the Humber Bridge made it's ferrying role on the Humber redundant.