The Louvre
The Louvre started as a military facility and retained military uses during most of its history. The initial rationale in 1190 for building a reinforced fortress on the western end of the new fortifications of Paris was the lingering threat of English-held Normandy. After the construction of the Wall of Charles V, the Louvre was still part of the defensive arrangements for the city, as the wall continued along the Seine between it and the farther west, but it was no longer on the frontline. In the next centuries, there was no rationale for specific defenses of the Louvre against foreign invasion, but the palace long retained defensive features such as moats to guard against the political troubles that regularly engulfed Paris. The Louvre hosted a significant arsenal in the 15th and most of the 16th centuries, until its transfer in 1572 to the facility that is now the Bibliothèque de l'Arsenal.