Église Saint-Augustin

Standing at a busy junction in the 8th arrondissement, this large 19th-century church was among the first in Paris to use an iron structural frame, engineered during the Haussmann era to fit a triangular site. Its eclectic facade rises to a tall dome that punctuates the surrounding boulevards, while inside slender iron columns support a vast interior of coloured decoration. Built by the architect Victor Baltard, better known for the market halls of Les Halles, it demonstrates how industrial techniques reshaped sacred architecture.