At the highest point of the neighborhood, the hill of Saint Genevieve, sits the imposing Panthéon. This neoclassical masterpiece was originally commissioned by King Louis the fifteenth as a grand church. However, during the French Revolution, it was repurposed into a secular mausoleum to honor France's greatest citizens. Inside the crypt, you will find the resting places of legends like Victor Hugo, Voltaire, and Marie Curie, who in 1995 became the first woman to be entombed here for her own scientific achievements. Don't miss the replica of Foucault's Pendulum swinging beneath the dome; it was used in 1851 to famously prove the rotation of the Earth. If you have the energy, you should climb to the colonnade gallery for one of the most stunning 360 degree panoramic views over Paris.