Church of Saint John the Baptist of Nemours, Nemours

Built starting in 1170 to house a relic of Saint John the Baptist brought back from the Second Crusade, this church blends Romanesque, Gothic, Renaissance, and Classical architecture across five centuries of construction. The oldest surviving element is the 12th-century bell tower-porch with its Romanesque archivoltes, while the choir and radiating chapels date from 1510-1550. Inside, the grand organ from 1654 retains the highest percentage of original 17th and 18th-century pipework of any organ in Île-de-France, classified as a Historical Monument since 1934.