In 1860, the park was purchased by the city, and in August 1861 Parc Monceau became the first new public park in Paris to be created by Baron Haussmann as part of the grand transformation of Paris begun by Emperor Louis Napoleon. Two main alleys were laid out from east to west and north to south, meeting in the center of the park, and the alleys within the park were widened and paved, so carriages could drive the park. An ornamental gate high was installed along a newly created avenue, "boulevard Malesherbes", curving paths were laid out around the park for strolling. The "pavillon de Chartres" was also modified by the architect, Gabriel Davioud, who had a graceful classical dome added to the structure. He also built a bridge modeled after the Rialto bridge in Venice over the stream to replace the Chinese bridge by Carmontelle that had once been there. He preserved the other follies remaining from the original garden. Haussmann embellished the park with a rich collection of exotic trees and flowers from around the world.