Saint Chapelle chapel

Sainte-Chapelle is not just a chapel. It is a gigantic reliquary turned into architecture. King Louis IX built it in the 13th century to house the Crown of Thorns of Christ, and he spent three times more on purchasing the relic itself than on building the structure. Today it is one of the most impressive Gothic monuments in Europe: almost all the walls of the upper chapel are replaced by 13th-century stained glass, which has survived to this day almost entirely.