L'église de la Madeleine is found in the Place de la Madeleine, just behind the Place de la Concorde. The neo-classical church took 85 years to build due to the wartime instability during that era. It’s located in the 8th arrondissement.
Napoleon imagined the place as a sort of grand temple in homage to his all-conquering Grande Armée at the beginning of the 19th century. Little by little, it became the Saint-Lazare train station and La Madeleine became a church. You can get there on the Metro line 14, getting off at the Madeleine stop.