TSS Duke of Lancaster is a former railway steamer passenger ship that operated in Europe from 1956 to 1979, and is beached at Llannerch-y-Mor Wharf near Mostyn Docks, on the River Dee, in north Wales.

She replaced an earlier 3,600-ton ship of the same name operated by the London Midland and Scottish Railway company between Heysham and Belfast.

[3][4] In this capacity, the Duke of Lancaster travelled to the Scottish islands and further afield to Belgium, Denmark, Netherlands, Norway and Spain.

In order to maintain ferry services whilst these modifications took place, Duke of Lancaster's duties as a cruise ship ceased.

[5][6] On 25 April 1970 the ship returned to service, having had her main deck rebuilt to accommodate vehicles via a rear door at her stern.

[5] Duke of Lancaster was then briefly employed on the Fishguard to Rosslare crossing, before becoming the regular relief vessel on the Holyhead to Dún Laoghaire service until November 1978.

[2] Duke of Lancaster arrived in Llanerch-y-Mor, North Wales from Barrow-in-Furness, in August 1979 to start her new life as a business venture and retail complex as "the Fun Ship" to circumvent the-then sunday trading laws as it did not apply to ships, the owner John Rowley saw this legal loophole.