The Vallée de Chevreuse is a "Parc Naturel" that lies about 25 kilometres from Paris. We had a short break there last week. It's carefully managed, with mapped out and waymarked hiking and cycling routes so that the tourists don't do too much damage. It's a pretty area, forested and dotted with towns, villages and chateaux. "Chateau" is usually translated as "castle" but "stately home" is a better translation most of the time. Proper castles built to withstand attack are easily identified as such.
Some such stately homes give the impression of being opened only grudgingly to the public, the owners chasing after the grants and tax benefits rather than wanting to offer a genuine visiting experience. Others, such as the Château de Breteuil offer an interesting day out. The building was taken over relatively recently with the intention of keeping it from decay, and turning it into an attraction. The chateau's own web site will tell you everything you need to know about it, but my attention was drawn towards a woman scientist who I had never heard of. Emilie de Breteuil, born in 1706, was the daughter of one of the barons who owned the place, she became Emilie du Châtelet upon marriage.
Her masterwork appears to have been the translation of Newton's Principia Mathematica into French. No mean feat. Granted, it's easier to follow someone's work than to do the original thinking, but firstly, the work was written in a sort of pidgin English/Latin and was hard to read in the first place, secondly you have to thoroughly understand what's going on or else you end up with a sort of mathematical "English As She Is Spoke", and thirdly, it remained the definitive translation into French until quite recently. (According to Wiki, it remains the standard, but the Chateau Guide told us that it has been superceded by a new edition)
According again to our tour guide, Emilie became pregnant in her early 40s by her new lover, and did her best to stay awake all hours to finish the translation, believing she would not survive childbirth. She was right.