I have walked past this doorway several times when it was ajar and did not step through. There is no courtyard beyond, only a hall. With both doors closed it is better to admire the architecture and style. The windows and balconies above indicate a nice place to live on this busy street and only two doors away from Dalloyau!
(This post is for Vreni, who loves the blue doors of Paris as much as I do)
To see more doorways go to Louis La Vache's porte-de-lundi.