text: Then , ruthless urban planner Baron Haussmann swept away almost all the medieval and 17th-century structures , leaving just place Dauphine and rue Chanoinesse ( ancient home of the cathedral canons ) as signs of the island 's once rich residential life .
  
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  When Baron Haussmann removed almost all of the medieval and 17th-century structures he nearly erased all signs of the island 's past .