On the left at No. 25, is the St. Polycarp church, recognizable from its classical and monumental facade with pilasters and Corinthian columns. It is the old church of the Oratorian order who settled on the slopes in 1642. The building was completed in 1670, with the exception of the façade which was designed by the architect Toussaint-Noël Loyer in 1756. The stone bell tower, planned for the northwest corner, was never built. In 1791, the church became a parish church and took the name of Saint Polycarp. It contains a large impressivesounding organ which was manufactured and installed by Augustin Zeiger in 1840; the walnut woodwork is by Bossan.