Place du Panthéon
Louis XV vowed in 1744 that if he recovered from an illness he would replace the ruined church of St-Genèvieve Abbey with an edifice to the glory of the patron saint of Paris: St-Genèvieve.
He got better, and thus began the construction of the Panthéon. It had a commanding view of the city. The overall design was that of a Greek cross with a massive portico of corinthian columns.