If you don't come early, you will have to wait to get in. Once you are inside... forget the present and welcome to the 19th century !
About the food : don't expect gastronomy !
This restaurant is unique, very cheap. Don't miss the experience !
Restaurant Chartier

If your hotel is in Saint Germain or the Latin Quarter, take the 85 bus from Saint Michel and twenty minutes later get off at "Grands Boulevards". If your hotel is near Invalides or the Eiffel Tower, take metro line 8 (Latour Maubourg) and fifteen minutes later get off at "Grands Boulevards".