The whole of the Place de la Concorde – the ground, fountains, statues, sentry boxes, balustrades, columns and lampposts – was classified as a historical monument by a decree of 23 March 1937. Since then, there have been no significant changes. Only the obelisk was embellished in 1998, on the initiative of the Egyptologist Christiane Desroches Noblecourt, by the installation of the gilded bronze pyramidion that tops it. This monumental square of 0.033 sq. miles (8.64 hectares) represents the most important urban development of the Enlightenment. It bears witness to the new classicism established by Ange-Jacques Gabriel, the architect of Louis XV.