Complex sentence: It is the work of architect Jean-Rodolphe Perronet (1708-1794) whose best known works are the Pont de la Concorde in Paris (1787-1791) and the bridge of Nantes.
Split into simpler sentences: It is the work of architect Jean-Rodolphe Perronet (1708-1794). His the best-known works are the Pont de la Concorde in Paris (1787-1791) and the bridge of Nantes.