Scotland, Glasgow, City Centre, George Square, Merchants House, window detail.

Scotland, Edinburgh, Scottish Parliament building, window detail.

Scotland, Edinburgh, Scottish Parliament building, window detail.

Scotland, Edinburgh, Edinburgh Castle, St Margaret's Chapel, Stained glass window with detail of St Columba.

Poland, Warsaw, Detail of colourful facades in Plac Zamkowy or Castle Square.

Poland, Warsaw, Detail of colourful facades in Plac Zamkowy or Castle Square.

Poland, Warsaw, Detail of colourful facades in Plac Zamkowy or Castle Square.

Poland, Warsaw, Stare Miasto or Old Town Square, Facades detail from the west side of the square.

Spain, Catalunya, Barcelona, Antoni Gaudi's Casa Batllo building, detail of dragon's back tile feature on the roof terrace with windows included.

Spain, Catalunya, Barcelona, Casa Batllo by Antoni Gaudi, detail of window exterior.

Spain, Catalunya, Barcelona, Casa Batllo by Antoni Gaudi, detail of window in the interior.

Spain, Catalonia, Barcelona, La Pedrera or Casa Mila on Passeig de Gracia, designed by Antoni Gaudi, window detail in the Apartment