Two short blocks away on Balcarce, tucked inside a larger building on the corner of Hipólito Yrigoyen, is the Antigua Sede del Congreso Nacional — the first permanent home of the Argentine legislature. The building was inaugurated in 1864 by President Bartolomé Mitre and served as the seat of Congress for four decades until the new Palacio del Congreso opened in 1906. The main structure was demolished in 1942, but the original debating chamber was preserved inside the replacement building, restored in the 1940s, and declared a National Historic Monument; it is now the home of the Academia Nacional de la Historia. It is easy to walk past without realising what survives inside — worth a look if it's open.