Poland, Krakow, Old Town, Barbakan or Barbican, Defensive gate.

Poland, Krakow, Old Town, Barbakan or Barbican, Defensive gate, Interior view.

Poland, Krakow, Old Town, Barbakan or Barbican, Defensive gate, Interior view.

Poland, Warsaw, Old Town, Barbakan or Barbican, Defensive gate.

Poland, Warsaw, Old Town, Barbakan or Barbican, Defensive gate.

Poland, Warsaw, Old Town, City wall with Barbakan or Barbican defensive gate in the background.

Poland, Warsaw, Old Town, City wall with Barbakan or Barbican defensive gate in the background.

Malta, Valletta, Cannon Battery overlooking Grand Harbour.

England, County Durham, Durham, The Keep, Durham Castle.

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

Ireland, County Tipperary, Cahir, Cahir Castle, General view of castle and surrounding wall.

Ireland, County Tipperary, Cahir, Cahir Castle, General view of castle and surrounding wall with stream running past.