We are now in front of the only vestige of Saint-Jacques-de-la-Boucherie church, probably raised here in the reign of Carolingian kings. We are now on a place which used to be very strategical: indeed, pilgrims used to leave here for Compostela.
The church, destroyed in 1797, kept its bell-tower built from 1509 to 1523 by Jean and Didier de Felin. During the Revolution, bells were melted, the saint Jacques' statue disappeared and they demolished the church supposedly to "clean the district"... The tower was sold in 1792 to a small shot maker, who devastated it.
In 1836, Paris city owned it and restored it. They made a brand new statue of saint Jacques and gargoyles, they added an octagonal foundation with 14 stairs. Since 1931, the tower became a weather station.
Oh, did you see that? Above the keystone, there's a statue of Pascal: the famous mathematician carried out his barometric experiments in the tower!