Inside the space of the church you can see its walls decorated with works by the artist Delacroix, whose must see piece is "Jacob Wrestling with the Angel." The windows of the church are also filled with magnificent stained glass.
In addition, the church is known for its impressive organ, which contains 6,588 keys and was built in 1862. The organ of Saint-Sulpice is one of the three "hundred stations" that exist throughout Europe. Besides necessary improvements and changes in the electronic and mechanical mechanisms, the organ is almost completely preserved.
In 1724 excavations were conducted in the vicinity of the church, revealing a tenth-century tomb. This proved that there was already a prayer house and a cemetery there.
Victor Hugo's wedding was inside the walls of the church.
The sundial is actually a line stretched across the floor that climbs an 11 meters high white marble pillar. At the top of the pillar is a ball with a cross. In the southern window, a lens system is installed so that the sun beam shines across the line. On the autumn equinox, the ray of the sun touches a copper elliptical plate that sits on the floor next to the altar. One of the reasons why Saint-Sulpice church was preserved during the French Revolution, while other churches were damaged and destroyed, was that the sundial was used for a variety of scientific experiments.
Shortly before the French Revolution broke out, the architect Jean-François Chalgrin, who also designed the Arc de Triomphe, planned the two towers that rose over the church. Some critics claim that the harmonious appearance of the church was damaged due to the mismatch between the pair of towers.
In the 19th century, following the damage of the revolution, the interior of the church, which now became the "temple of victory", was redesigned. Frescoes painted by renowned painter Eugene Delacroix were added. These adorn the walls of the side chapel. The most famous paintings are "Jacob Wrestling with the Angel" and "The Expulsion of Heliodorus."