Work began on the iconic Church of St Sulpicius, with its two towers and 21 side chapels, in 1646. It took six architects a total of 150 years to complete the building, known for its impressive Italianate façade with two rows of columns, its neoclassical decor inspired by the Counter Reformation period, its frescoes by renowned French painter Eugène Delacroix – and its appearance in Dan Brown’s The Da Vinci Code. The 1781-built organ can be heard during Sunday Mass at 10:30am or the occasional afternoon concert.