Almost everyone recognises the Florentine Skyline which is invariably dominated by Brunelleschi's curved red-tiled dome however, it is not until you see the Cathedral first hand that the scale of this architectural masterpiece hits you. The magnitude of the cathedral is such that for over 200 years it had no Dome as they couldn't devise a way of making scaffolding high enough without it collapsing under its' own weight...
So how did they solve the problem of the Church with no Dome - well back in the early days of the renaissance Brunelleschi won a public competition to design the enormous dome, which was achieved by constructing the scaffolding from one side of the cathedral to the other rather from the ground up. Brunelleschi also used a revolutionary type of brickwork called herringbone i.e. where the bricks were interlocked in a very similiar fashion to the way children playing with Lego today. Of course the herringbone brickwork, ingenious as it was, would not alone have been enough to stop the dome collapsing inward. Brunelleschi's real stroke of genius was in creating a kind of circular skeleton over which the external octagonal structure of the dome took shape. Although nowadays the Dome is severely cracked and under restoration, it remains a remarkable achievement of design.