You'll find a whole lot of interesting information about it, here. But I really liked the little study I found here. I never knew that the word "loo" used by my British friends (God forbid anyone should say "toilet") actually came from the French. And the reason why is hilarious. Of course, after visiting a few medieval castles over the summer, and hearing about the habits of the time, I can't say I'm surprised that the servants would throw the content of the bedpans out of the windows with a simple warning : "regardez l'eau." And of course, all the stories about our kings' habits have entertained French children for the longest time (maybe also children in other countries, but I have no experience, there.)
I also found it interesting that the Esperanto language uses a word so similar to the American word I'm trying to translate as accurately as possible. Necesejo.
But I'm paid to translate into French, not into Esperanto, and so I may have to settle for Le Petit Coin - if it was good enough for Molière, it's good enough for me, too - even though I'm not entirely satisfied. "Petit coin" (little corner) has something cute about it that doesn't match the more down to earth, austere feeling of the word "necessary."
So, was that an interesting entry, or what?