Added museum: Musee des Arts et Metiers, 60 rue Reaumur, 3e. Essentially a museum of the history of technology and industrial design, founded 1794 as part of the Ecole des Arts et Metiers. And don’t miss the fascinating walls of its adjoining Metro station.

Added church: Saint-Eustache, one of the oldest and largest, at Les Halles (rue des Coquilleres, almost next-door to Pied de Cochon. Beautiful interior, also has concerts (excellent acoustics and an 8000-pipe organ) and the fabulous Raymond Mason sculpture of the market workers leaving Les Halles for the last time.

Added park: Parc des Buttes Chaumonts, in the 19e. A former quarry with other questionable history, under Napoleon III, Hausmann had it turned into a verdant wonderland, with water features, a folly or two, cafes, rocky cliffs and even Paris’s only suspension bridge, built by Gustave Eiffel. I have a blog on it at http://www.travelgumbo.com/blog/parc-des-buttes-chaumont-paris-a-park-with-a-past

Added detail: Covered passages. There are quite a few more, including some fascinatingly scruffy ones off Rue du Faubourg Saint-Denis, and more stunningly beautiful ones. John Brunton of the Guardian (UK) had a good piece on them a few years ago at http://www.theguardian.com/travel/2012/mar/02/paris-hidden-passages-shopping-shops

And a small correction: Montmartre Cemetery is nowhere adjacent to Sacre Coeur; it’s a bit over a kilometer to the west, a 20-minute walk…and it’s well downhill from the heights where the basilica sits.

Between them, by the way, is one more church worth a close look, right at the Abbesses Metro station. It’s Saint-Jean-de-Montmartre, built at the turn of the 20th century, with moderniste design and industrial materials. Worth a look…I have a blog at http://www.travelgumbo.com/blog/saint-jean-de-montmartre-an-art-nouveau-church-in-paris