The distinctive small stone tower was built in the late 1700s. It was one of a pair of watch towers which guarded the bleach green at Tullylish near Gilford in County Down. The building was dismantled and moved to the Folk Museum in the 1960s.
The tower provided shelter for a watch man. His duty was to guard the long rows of newly woven linen laid out on the green to bleach in the sun. This was before the introduction of chemical bleaching.
In the 1700s, Bleach green keepers or Watchmen were needed because parts of the Ulster countryside had no field barriers or gates. Grazing animals had to be stopped from coming onto the bleach green because they would damage and mark the linen. The watch men also guarded against theft. Stealing cloth from bleach greens was not uncommon and the cloth would be relatively easy to sell. The punishments could be harsh if you were caught.
Look at the view afforded by the tower over the bleach green so as to alert the watchman from straying animals or thieves.