The Panthéon also contains a crypt where a number of important historians, philosophers, scientists and writers are buried, including Voltaire, Jean-Jacques Rousseau and Marie Curie. You can ...

U.S. News Insider Tip: After visiting the Pantheon, stop for an espresso at the historic Tazza d'Oro Caffè or walk a few blocks to the old-school gelateria, Giolitti, for a cone of the good stuff.

The crypt houses the remains of Voltaire, Rousseau, and other luminaries who championed the ideals of reason and progress.