Rione III Colonna on Tavola 3, a narrow band running from the Camera dei Deputati and Piazza Colonna towards Via del Tritone and the Ludovisi edge.
Source: Old map, public domain
Labels on the pink streets name the Camera dei Deputati, Palazzo Chigi with the Presidency of the Council of Ministers, and Piazza Colonna. A Posta e Telegrafi building and the churches of San Lorenzo in Lucina and Sant'Andrea delle Fratte appear in the northern half.