Describe symbolism in Reading in the Dark by Seamus Deane

Grianan is the name of the ruins of an ancient hill fort. It consists of a stone ring with worn steps on the inside leading to a parapet which looks out over the countryside. From one inside wall led a secret passage with a slabbed stone "chair" at one end, which was the site of Eddie's killing. The locals believed that legendary warriors were buried beneath the fort, waiting for the time when they would banish the British from Ireland forever.