Here is an interesting part of Paris. To the East you can see St Sulpice church, a high example of French classical architecture; with some 17.000 sq m of built surface, a grand and complex monument. The urban tissue is quite dense, with a rather irregular street pattern. Boulevard Raspail somehow blurs the legibility of that area in the XIXth century; city blocks west of that line, with so few buildings, are in fact baroque palaces, mainly along the Rue de Babylone. On the same Rue de Babylone, at Place Le Corbusier (!), close to Boulevard Raspail, you have a quite dense building: Le Bon Marché, a pionneer department store, which I think is even more interesting as architecture than the ones around Opera Garnier. I even worked there for a week under the roofs, in an architectur practice. With some 34.000 sq m of built up area, a building worth visiting.