Notable buildings, structures and parks designed by Formigé include the Pont de Bir-Hakeim (1905); the Viaduc d'Austerlitz (1904); the dramatic sloping park in front of the Basilica of Sacre-Coeur in Paris; the Square d'Anvers, the Square des Epinettes and the square in front of the Arenes de Lutece in Paris; the monumental greenhouse of the Jardin des Serres d'Auteuil (1895-1898); the Columbarium at Pere-Lachaise cemetery in Paris; the restoration of the Roman amphitheater and theater in Arles, France; and the restoration of the Roman theater at Orange, France. He restored the Abbey of Conques (1878) and the Tower of Saint-Jacques, across from the Louvre, in Paris. He also designed the Palace of Fine Arts and the Palace of Liberal Arts, two of the major exhibition halls at the Paris Universal Exposition of 1889.