England, County Durham, Durham, Entrance to Durham Castle.

Ireland, County Meath, Trim Castle, The Keep.

Ireland, County Meath, Trim Castle.

Ireland, County Meath, Trim Castle.

Egypt, Alexandria, Citadel of Qaitbay, also known as Fort of Qaitbay.

Egypt, Alexandria, Citadel of Qaitbay, also known as Fort of Qaitbay.

Spain, Catalonia, Barcelona, El Barri Gotic, Entrance gates of the Capitania General military headquarters.

Spain, Catalonia, Barcelona, El Barri Gotic, Entrance gates of the Capitania General military headquarters.

England, London, The White Tower, Tower of London.

England, London, The White Tower, Tower of London.

Mexico, Veracruz, Baluarte de Santiago, historic fort now site of museum with palm tree and flowering shrubs in foreground.

France, Brittany, WW2 German fortification at the Pointe du Petit-Minou at the entrance to the Straits of Brest located just behind the lighthouse.