Marché de la Chapelle.
Ironically, perhaps, bearing in mind not only the basilica's religious function but also its more nationalistic and political associations, since these days the ambiance of the whole area is distinctly North African - as in this display of finery.
But domes seem to have had a fascination for entirely secular builders and designers in the nineteenth century. The Galeries Lafayette have their dome-lit atrium (and on the upper floors you can see its outside):
The Petit Palais (built for an international exhibition) bears the badge of Paris, flanked by angels and all sorts of decorative detail:
And though the Pantheon, dominating the southern view from the roof of the Galeries Lafayette as the Sacré Coeur does the north, was built earlier and as a church, it's echoed - even challenged - by the dome of the Opera House, with embellishments that no-one could have been expected to see from the ground: