The National Museum of Natural History is unlike any other I’ve been to. It is fairly worn out but is great. It is displayed in a very different t format to what I’m used to. https://en.m.wikipedia.org/wiki/National_Museum_of_Natural_H...

Quiet and completely excellent, The Museum of Heritage and Architecture. https://www.unjourdeplusaparis.com/en/paris-culture/musee-ci...

The Army Museum is worth a visit - it is interesting to see a less Anglo centric view of the wars, particularly WW1. The paintings are deeply grim - not ideal if you have young kids. https://en.m.wikipedia.org/wiki/Musée_de_l%27Armée

The Museum of the Middle Ages is currently being renovated but is well regarded. https://en.m.wikipedia.org/wiki/Musée_de_Cluny_–_Musée_natio...

Probably a candidate for best museum in the world, the Louvre is a great way to completely waste a day with massive crowds, sore feet, food and water shortages, closed exhibits, intense heat and even more crowds. Get a map ahead of time and check that the things you want to see aren’t closed before you go.