City Hall, Turin: Detail, center section of the facade

Lanfranchi's most prominent secular building is the Palazzo di Citt\u00E0, which was commissioned by the municipality in response to the Palazzo Reale, the ducal residence begun by Amedeo di Castellamonte in 1658. Unlike the Palazzo Reale, however, the fa\u00E7ade of the Palazzo di Citt\u00E0 is ornamented with the architectural orders in the form of pilasters. The central section has an entrance resembling a triumphal arch. The building was later enlarged by Benedetto Innocente Alfieri, who added the side wings (from 1756), and modified by Francesco Valeriano Dellala di Beinasco (1731-1803), Filippo Castello (1738-1818) and others.