The church started out as a Romanesque basilica, constructed in the 13th century. In the mid-17th century, the people of the parish of St-Sulpice were considered one of the most sinful in all of Paris. Jean-Jacques Olier, the abbot recently placed in charge of the church, was determined to change that. He founded the religious congregation of Saint Sulpice, which would work to change the local religious lifestyle. Olier also ordered a new church built on the site of the old one, transforming the basilica into a grand Neoclassical structure. Anne of Austria laid the first stone in February 1646.

But numerous financial problems slowed construction on the church, which would ultimately take nearly 130 years to complete ! The imposing western façade, designed by the architect Servandini, was completed in the 1770’s. It is made up of three levels, and has two large porticoes, in Doric and Corinthian styles. In 1777, the architect Chalgrin made improvements to the church’s northern tower, but the outbreak of the French Revolution stopped him from completing work on the southern tower. Ever since, this latter has always been smaller than its twin. Over time, the different-sized towers has become one of the church’s most easily spotted trademarks.

Another of Saint-Sulpice’s claims to fame is the fact that it is the second-largest church in Paris, only slightly smaller than Notre-Dame. Saint-Sulpice is also well-known for its organ, one of only three 100-stop organs in all of Europe (the other two are located in Ulm Cathedral and Liverpool Cathedral). Restaured and expanded in 1862 by famous 18th century organ maker Aristide Cavaillé-Coll, the organ was inaugurated the following year in the presence of grand musical personalities like César Franck and Camille Saint-Saëns. Today, a concert at Saint-Sulpice is a wonderful experience for music lovers, who will appreciate the skill of the musician, as much as the church’s celebrated acoustics. Saint-Sulpice also contains numerous works of art, most notably Eugène Delacroix’s frescoes in the Chapelle des Anges (Angels’ Chapel), among them the famous Lutte de Jacob avec l’Ange (Jacob Wrestling with the Angel).

But most interesting of all to fans of The Da Vinci Code and of conspiracy theories in general, is the church’s gnomon. A gnomon is an astronomical instrument of pagan origin used to measure the variations in the sun’s height at noon. The one here was built in 1727 to determine the date of Easter each year. The gnomon in Saint-Sulpice works with the use of a meridian line, which is marked out in brass on the floor, running in a north-south direction, and up a wall onto a white marble, Egyptian-style obelisk. The sun’s rays are projected through a series of optical lenses located in a window, and form a luminous disk that travels along the brass meridian line, moving progressively throughout the year.

But beyond the scientific and useful aspects of the gnomon, Da Vinci Code readers who come to see it recall above all that it’s in a hollow space at the foot of the white obelisk that Silas discovers what could be the key to the mystery he’s trying to solve. Because in his novel, Dan Brown uses the gnomon as a device with a strong occult significance. He sees in its brass line a marker showing the location of an ancient temple dedicated to the goddess Isis, that once stood on that very spot. More especially, he sees that the space occupied by the church’s keystone could reveal a secret that the Priory of Sion has long kept hidden. Dan Brown also notices the letters “P” and “S” inscribed in some of the church’s windows. Would it possibly be the initials of the secret society ? Historians and those in charge at St-Sulpice are quick to point out that these letters are not here because they stand for the “Priory of Sion,” but rather because they honor the church’s two patron saints, Peter and Sulpitius the Pious.

Brown also claims that the gnomon’s brass line follows the Paris Meridian, or “Rose Line” (2°20′14.025″ east), a line of longitude that almost became the official Prime Meridian in the 1880’s. In fact, the Paris Meridian is located several meters over from the gnomon’s marker. Still, this Meridian, which plays a vital role later in the book, does also have its mysterious associations. Some have considered it a line of evil. Some consider it a pathway to finding the location of the Holy Grail.

Fact or fiction – it’s for you to decide. We suggest re-reading the chapters of The Da Vinci Code that take place in Saint-Sulpice, and, of course, to come visit this impressive church to experience the myth and reality that are tangible here. Not to mention taking a moment to gaze at Delacroix’s gorgeous frescoes…. Then, try to follow the real Paris Meridian, which is marked by commemorative “ARAGO” medallions created in 1994. Who knows what you’ll find along the way? Happy searching!