Helen's Tower is a 19th-century folly on the Clandeboye Estate in Bangor, Northern Ireland. The tower was commissioned by Lord Dufferin of Clandeboye, designed by Scottish architect William Burn and completed in October 1861. The tower was named in honour of Dufferin's mother, Helen Selina Blackwood, the Lady Dufferin. The tower inspired a number of poems, which were inscribed within the building. During the First World War, soldiers of the 36th (Ulster) Division trained at Clandeboye before being sent to the front line, and the landmark tower was chosen as the model for the Ulster Tower, a monument erected at Thiepval in 1921. Helen's Tower was restored in the 1980s and is now a holiday let managed by the Landmark Trust. It is a grade A listed building, recognised as "one of the two finest memorial towers in the country".