This curved part that is visible from the street is a small attic and is said to be the flank of the dragon slain by the patron saint of Catalonia, St. George. Not only is the shape fascinating, but the metal covering and balls running along its edge both change color as they progress around the hump and end up being yellow to orange and green to blue, respectively, on the other end. The small opening in the attic has a parabolic shape and reminds of the "Roca Forada" of the mountain of Montserrat (according to "Visual Guide, Casa Batlló").