Oysters

I know I can't be the only one to come in here ready to type out info on London transit passes...

This place gets high marks.
La Cabane à huîtres
4 rue Antoine Bourdelle
http://cabane-a-huitres.fr/

Want to stay in Montparnasse or branch out? If you are willing to travel try, Le Baron Rouge morning n the 12th. https://parisbymouth.com/our-guide-to-paris-le-baron-rouge/ In Montparnasse, how about Le Dome. It's quite pricey IMO. Here are a bunch of places https://parisbymouth.com/tag/oysters/. I've been to most of them (not been to the last two) and they have all been very good.

Thank you.

Baron Rouge, on the edge of the Aligre market, is as old-fashioned as it can manage. Tiny, merry, with a complicated open-close schedule. Food takes second place to the wines, still dispensed by the plastic jug from the barrel if you want it. Worth a visit just for the atmosphere. Saturdays and Sundays are so crowded with locals that your only space may be on the pavement.

We found the best raw oysters, and best seafood in general, at a wonderful place at intersection of Rue de Vaugirard and Boulevard Victor right across from the Porte de Versailles metro station. The restaurant is on your left as you are facing Rue de Vaugirard. It's an easy metro ride from Montparnasse and a straight walk down Rue de Vaugirard (the longest boulevard in Paris, so I was told), so you can walk off your fabulous meal. The French equivalent of our "seafood tower" was so overwhelming we really didn't need to have ordered anything else, but already had. Their salmon fume was better than I've had in the Pacific Northwest (sorry Oregon, and Seattle). The service was impeccable. It was truly a highlight of our month-long stay in Paris. I regret I only have the location, not the name. We dined there the day before we left! :( Otherwise, we would have gone back.

Huitrerie Regis in the 6th. It is tiny but if you can get a seat it is so worth it. Read Meet Paris Oyster: A Love Affair with the Perfect Food by Mireille Guiliano before you go.