A common theme most anywhere on the island is that of steep volcanic mountains and hillsides, and Saint-Denis is no exception, the West side of town is pretty much defined by a giant, steep mountain: (that, like many things in Reunion, has no specific name, just being called "La Montagne")
The rare picture of myself from my own camera (looking a bit worn after my flights):
Despite a bit of the European or Caribbean feeling to the town, you quickly can tell that you aren't in one of these areas, since Reunion has a pretty sizeable Muslim population, so in the larger cities (Saint-Denis and Saint-Pierre), you can see the Mosques and hear the calls to prayer, with you here being able to see the Saint-Denis Mosque looming over one of the pedestrian malls in Saint-Denis.
The town also has possible the most non-descript McD's I've ever seen (which, oddly, was selling something called the "Chicago Supreme Burger"):