As the centenary of the French revolution approached, Formigé suggested building a monument commemorating the famous Fête de la Fédération organised on the 14 July 1790. This ceremony celebrating the fall of the Bastille was held on the Champ de Mars in the presence of King Louis XVI. It brought together representatives from all classes and all provinces of France in a setting filled with lavish, ephemeral decorations, to celebrate liberty and the rights of the French people. Naturally, Formigé suggested building his monument on the Champ de Mars.
Having specialised in ornamentation during his time at the School for Decorative Arts in Paris, the architect proposed a delightful circular temple, a sort of tholos, placed on a huge platform surrounded by a balustrade. The whole thing was further enhanced by large allegorical winged figures and equestrian statues of Fame blowing a trumpet. Finally, the dome is surmounted by allegorical statues representing Liberty, Equality and Fraternity.
Curiously, the building refers more to the famous Follies with which the 18th century nobility like to embellish their gardens, than to the austere Neo-Classicism of revolutionary designs. But Formigé completely changed its proportions, giving it impressive dimensions, and his eclectic decoration made it very typical of its time.