Merlin Castle, or sometimes known as Doughiske Castle, is a three storey 16th century tower house ruin in Galway City.
The castle was built for Turlough O’Connor who was one of the last High Kings of Ireland. The castle was inhabited until the mid-19th century. Although now in ruin, the castle remains in relatively good condition.
Interestingly, there is a Sheela na Gig which can be seen sitting upside down on a decorated window on the second floor.