Hook Head Lighthouse is the oldest operating lighthouse in Ireland, and one of the oldest in the world.  The present structure has stood for nearly 800 years. 

The phrase "By Hook or by Crook" may have originated because of this lighthouse when Strongbow, the Earl of Pembroke, sailed into Waterford Harbour in 1170 and saw the lighthouse on one side and the church of Crook on the other, saying "We must take the town by Hook or by Crook".