The Panthéon, an imposing 19th century building, was first designed as a church, but later turned into a civil temple.
On top of the montagne Ste-Geneviève, not far from the Sorbonne University and the Jardin du Luxembourg, the Panthéon looks over the Quartier Latin. As far back as 507, this site was chosen by King Clovis - the first Frankish Merovingian King - for a basilica to serve as a tomb for him and his wife Clothilde. In 512 Sainte-Geneviève, patroness of Paris was buried here.
When King Louis XV suffered from a serious illness in 1744 he vowed to build a church dedicated to Sainte-Geneviève if he would survive. After he recovered, he entrusted the Marquis of Marigny with the task of building the church, which was to replace the 6th century basilica, at the time known as the Abbey Sainte-Geneviève. In 1755, the Marquis commissioned architect Jacques- Germain Soufflot to design a new, great church.
Construction of the imposing building started in 1757. Mainly due to financial problems, it would take 34 years until the project was completed. After Soufflot's death in 1780, his associate Guillaume Rondelet took charge of the project. The building was finished in 1791, in the midst of the French Revolution. That same year, the Constituent Interior of the Panthéon Assembly of the Revolution decided by decree to transform the church into a temple to accommodate the remains of the great men of France. The building was adapted by architect Quatremère de Quincy to its new function as a pantheon. In 1806 the building was turned into a church again, but since 1885 the Panthéon serves as a civic building.
The floorplan shows a Greek-cross layout, 110m long and 85m wide (361 x 279 ft). The large dome reaches a height of 83m (279ft). The portico, with large Corinthian columns was modeled after the 2nd century Pantheon in Rome.
The dome features three superimposed shells, similar to the St. Paul's Cathedral in London. Iron reinforcements were added to strengthen the structure even more. The large crypt, covering the whole surface of the building accommodates the vaults of great French public figures. Some of the most famous buried here are Victor Hugo, Voltaire, Jean Monnet, Marie and Pierre Curie and Emile Zola.
The Panthéon was also the place where, in 1851, the astronomer Jean Bernard Léon Foucault first held his famous experiment, proving that the world spins around its axis. The Foucault pendulum moved in 1851 to the Conservatoire des Arts et Métiers (3e arr). In 1995, it temporarily moved back to the Panthéon due to construction works at the Conservatoire.
From the colonnade around the building's dome, you have an excellent view over Paris. For safety issues you can only go up there in company of a (free) guide at regular hours. The Panthéon itself is best seen coming from the Jardin du Luxembourg through the rue Soufflot.