Ireland, County Waterford, Ardmore, St Declan's Monastic site, Ardmore Round Tower.

Ireland, County Waterford, Ardmore, St Declan's Monastic site, Ardmore Cathedral, the west gable with its carved arcades and the round tower behind.

Ireland, County Waterford, Waterford city, Reginalds Tower which was built by the Anglo-Normans after their conquest of Waterford, replacing an earlier Viking fortification.

Ireland, County Waterford, Waterford city, Reginalds Tower which was built by the Anglo-Normans after their conquest of Waterford, replacing an earlier Viking fortification.

Ireland, County Laois, Timahoe Round Tower.

Ireland, County Laois, Timahoe Round Tower partly framed by a wall of a monastic ruin with a former Church of Ireland church which is now a heritage centre.

Ireland, County Laois, Timahoe Round Tower partly framed by a wall of a monastic ruin with a former Church of Ireland church which is now a heritage centre.

Ireland, County Laois, Timahoe Round Tower partly framed by a wall of a monastic ruin with a former Church of Ireland church which is now a heritage centre.

Holland, Rotterdam, The Maritime Museum, The Low Light of the Hook of Holland lighthouse that once stood at the Hook of Holland, but has since been dismantled and reassembled at the Rotterdam maritime...

Holland, Rotterdam, The Maritime Museum, The Low Light of the Hook of Holland lighthouse that once stood at the Hook of Holland, but has since been dismantled and reassembled at the Rotterdam maritime...

Ireland, County Mayo, Killala, Killala Round Tower.

Republic of Ireland, County Kildare, Castledermot, Romanesque doorway in front of St James Church which is Church of Ireland and a 10th century Round Tower in the background.