The Arc de Triomphe de l’Etoile was completed in 1836. After developing the Champs-Elysées, the architect Jacques Ignace Hittorff obtained permission in 1854 to demolish the wall and the two octroi buildings that lined the Place de l’Etoile. He thus created an open crossroads square 240 metres in diameter from which twelve wide avenues lead off. Around the square, twelve lots were delimited, built of private mansions of similar architecture, with gardens facing the square, limited to a height of twenty-one metres. The prefect Haussmann, in disagreement with Hittorff, had clumps of trees planted in front of the mansions to conceal them.