Ireland, County Kerry, Killarney, Ross Castle, 15th-century tower house and keep on the edge of Lough Leane in Killarney National Park, the ancestral home of the Clan O'Donoghue.

Ireland, County Kerry, Killarney, Ross Castle, 15th-century tower house and keep on the edge of Lough Leane in Killarney National Park, the ancestral home of the Clan O'Donoghue.

Spain, Castile, Segovia, Iglesia de la Vera Cruz or Church of the True Cross (1208) located below the Alcazar.

Austria, Tyrol, Innsbruck, Altstadt, Stadtturm or City Tower built between 1442 and 1450 as an observation point for sentries and which was part of the City Hall.

Austria, Tyrol, Innsbruck, Altstadt, Stadtturm or City Tower built between 1442 and 1450 as an observation point for sentries and which was part of the City Hall.

Austria, Tyrol, Innsbruck, Altstadt, Stadtturm or City Tower built between 1442 and 1450 as an observation point for sentries and which was part of the City Hall.

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...

Holland, Rotterdam, The Cube Houses, an innovative housing development where each house is a cube tilted over by 45 degrees, designed by Dutch architect Piet Blom and bult between 1977 and 1984, Abstr...

Holland, Rotterdam, The Cube Houses, an innovative housing development where each house is a cube tilted over by 45 degrees, designed by Dutch architect Piet Blom and bult between 1977 and 1984, Abstr...

Ireland, County Wicklow, Enniskerry, Powerscourt Estate House and Gardens, The Pepperpot Tower.

Ireland, County Leitrim, Dromahair, Parkes Castle, Wishing well in the courtyard with a tower located on the defensive walls.