Pinnacles are typically made of stone and predominantly used for ornamental purposes, providing vertical emphasis breaking up hard outlines. In the case of some buildings, such as the Milan Duomo, they are topped with statues.
They can also serve a secondary structural purpose, crowning the piers of flying buttresses, where, being very heavy and often rectified with lead, they improve the stability of the buttresses, helping to counteract the lateral thrust of the vault, and shifting it downwards to the foundations.
Simple pinnacles were originally used on Romanesque churches, often as a means of distracting from the often abrupt transition from a square tower to a polygonal spire.
They became more common in Gothic architecture, where they were used in a much more decorative way, found at every major corner of a building, as well as on flanked gables and decorated parapets and buttresses.
Notable examples are to be found on Notre Dame in Paris, and the 24 m (80 ft) pinnacles of Reims Cathedral.
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