The Metro stop Filles du Calvaire is on line 8 coming either from Balard or Creteil.
The metro station is right on Boulevard du Temple which separates the 3rd from the 11th district in Paris. This stop is an ideal starting point to be walking down through the Marais towords the Seine and Notre Dame Cathedral. The only thing you need to do is walk down rue Vieille du Temple and keep on going straight. The road will take you also to the Musée Picasso, several well-know galleries and shops.
Line number 8 will take you to Place de la Bastille, but also Opera, Madeleine, Place de la Concorde and Invalides some of the most impressive sights in Paris.