Deep under the Louvre the well-preserved moat is open to exploration. The Louvre was once a fortress, and the moat is a reminder. Militarism and culture. This theme reverberates all over Paris whether you regard the Housmann urban plan, the Pere Lachaise cemetery, or the bronze-age statuettes and spearheads at the Louvre. Certainly the moat itself tells that story.
As a deeply historical city there is so much history in Paris that is buried or untold. An ancient settlement that pre-dated the Romans, the city has built and rebuilt itself, sometimes with little regard to the past, sometimes with a deliberate strategy to suffocate history.