Saint-Chapelle was built on the orders of Saint Louis, who wanted to build a shrine for the adoration of relics he had acquired, within his Palais de la Cité residence. Oral tradition attributes this major work to architect Pierre de Montreuil, who in fact built two chapels: the low chapel, dedicated to the Virgin and destined for the general public, and the high chapel, whose beauty has attracted visitors since 1248. This is where the 15 exceptional stained glass windows, more than 15 metres tall, can be seen. They were the focus of a major renovation project starting in 2008. A statue of the archangel Gabriel seems to watch over it all. The relics, in particular the crown of thorns and a piece of Christ's cross, are now part of the Notre-Dame-de-Paris treasury.