Once you’ve seen a Calatrava building, there’s no mistaking any of his works. The Spanish architect has a unique way of playing with lines, curves and open spaces, that makes his projects recognisable from afar. He specialises in monumental structures that combine form and function, like bridges, stadiums and railway stations. Often his works resemble living organisms: a Calatrava building never has just straight lines and surfaces; curves and domes give life and movement to his creations. A sculptor as well as an architect, he seeks out simple forms that elicit an emotional response in the observer, making them a perfect subject for many of our talented photographers.