The Mansion House The Mansion House is an elegant Georgian house in St Helen's Square, and is home to the city's Lord Mayor during their year in office. The foundation stone was laid in 1725 and the building completed seven years later. It houses the civic plate, a collection of silver and mementoes. The house is not normally open to the public except when the Lord Mayor holds `at homes`, although tours can be arranged by contacting the Civic Secretary.