From the top of the Tour Montparnasse, the Left Bank of Paris is not across the way, but just below where you are standing. I know I've already posted a photo of the Eglise Saint-Sulpice, but here's another, slightly different one:
I've also already posted a photo of the Pantheon in this series, but again, here's another, from slightly farther out. The big charcoal-gray high-rise building behind it is the recently re-furbished tower of the Jussieu university complex:
More to the west is the abbey church called Saint-Germain-des-Prés. It's one of the most ancient churches in Paris,with origins in Roman times. One early church building here was sacked by invading Vikings in the 8th or 9th century, and the church was rebuilt a century or more later.
Below is a stitched-together image of part of the Palais du Luxembourg (the cupola) and the blocky Théâtre de l'Odéon behind it.
I'm not yet finished posting these photos taken at the top of the Tour Montparnasse. Here in Saint-Aignan, life now is devoted to processing tomatoes and other garden produce...