Featured in Dan Brown’s best selling novel, The Da Vinci Code, Saint Sulpice Church saw it’s popularity rise as the book gained a cult following. However, Ron Howard (director of the movie version of The Da Vinci Code) was denied permission to film inside so when visited during the movie it isn’t the actual church.
The popularity was such that they had to add the following near the entry way so that tourists wouldn’t search for the ‘Rose Line’
(…) Contrary to fanciful allegations in a recent best-selling novel, this [the line in the floor] is not a vestige of a pagan temple. No such temple ever existed in this place. It was never called a «Rose-Line». It does not coincide with the meridian traced through the middle of the Paris Observatory which serves as a reference for maps where longitudes are measured in degrees East or West of Paris. (…) Please also note that the letters «P» and «S» in the small round windows at both ends of the transept refer to Peter and Sulpice, the patron saints of the church, and not an imaginary «Priory of Sion».