For years it was thought to have been built in 1450, but during restoration work experts dated the building much earlier.
At different times it has been the Town Hall, Council Chamber, a Court, a British restaurant during World War II and is currently a Museum. It was also used for banquets or any celebrations for the town.
It is also believed to have been the place where William Brewster, William Bradford and their followers (later to be known as the Pilgrim Fathers) were imprisoned following their arrest after trying to flee England.
In 1515, St Mary's Guild spent £20 on a single feast that they celebrated in the banqueting hall, £9,500 in today’s money. In contrast it cost 1 shilling to have a meal at the British Restaurant in 1943 - the modern equivalent of only £1.30!