transportation from Place de Concorde to Notre Dame

It's a pretty enjoyable walk, maybe a mile and a half along the river. If that won't work, cross to the right bank and ride Metro 1 from Hotel de Ville straight to Concorde.

I think Ed meant to ride the Metro from Place de la Concorde (Right Bank) to Hotel de Ville (Right Bank), then walk across the river to Notre Dame (Left Bank). Thing is you'll do a lot of walking and stairs taking the Metro, so really, you might as well just walk there. It's really not far and is a nice walk along the river. Ed's right, I Googled it, it's 1.59 mi. If you have mobility issues I would take a taxi or a bus, not the Metro.

Yeah, the other way.