Saint Sulpice, also known as the Cathedral of the Rive Gauche, meaning the Left Bank, is the second-largest church of Paris, after Notre Dame. It was originally constructed in the 12th century but its current architectural structure dates back to the 17th and 18th centuries. The reconstruction began in 1646, but due to the lack of available funds it took 140 years for the project to be completed. During a period of more than a century, the construction and design were undertaken by several architects. During the French Revolution, the church was converted into a temple of Victory. As a reminder of the revolutionary spirit of the times, an inscription on the lintel of the entrance’s interior has been preserved until today. Saint Sulpice is among the few churches that feature a gnomon in their interior. It was commissioned to the astronomer and clock maker Henry Sully by a priest, as he wanted to efficiently calculate the dates of the equinoxes and solstices.