This sculpture, by the artist Clíodhna Cussen, is to be found in Gort na gCeann (=the Field of the Heads) on the promontory of Dún an Óir at Smerwick in Co. Kerry. It commemorates the massacre of many hundreds of Spanish, Italian and Irish troops who were subsequently beheaded.
An interesting and very readable article on this may be found here: http://www.timesonline.co.uk/tol/news/uk/article822086.ece