The first Jesuit mission arrived in Peru in 1568 and its target was to convert natives to Catholicism. In 1608, the mission settled in Buenos Aires, close to the current Plaza de Mayo, where Jesuits built their first house, church and school in Argentina. Since the place where Jesuits were located had become dangerous, on May 25, 1661, they moved to a new land located on Alsina, Moreno, Bolívar and Peru Streets, in Downtown Buenos Aires. In 1686, Jesuits started to build San Ignacio Church and School, which still maintains the oldest tower in Buenos Aires. Almost two centuries after that, in 1821, El Argos newspaper named the place Manzana de las Luces (Light Block) due to the great variety of cultural and educating institutions that worked inside its walls.
Manzana de las Luces is a very important place in Argentina, since, throughout the centuries, it has been the stage for many historical moments: the Sala de Representantes 
(Representatives Chamber) was inside its walls from May 1, 1822, to the end of the 19th century; Bernardino Rivadavia took the oath as President in one of its rooms; the University of Buenos Aires used one of its widest chambers as the main lecture theater of Architecture School until 1972; etc. Besides, Manzana de las Luces hides a mystery: its tunnels, which run under the City of Buenos Aires. Found in the city center and San Telmo, and even in Recoleta neighborhood, the tunnels used to connect the churches and government buildings of the colonial city. For all these reasons, in 1942, Manzana de las Luces was declared a National Historical Monument and, in 1983, it underwent a restoration in order to receive visits from both locals and tourists.
Undoubtedly, walking around Manzana de las Luces allows visitors to relive the history of the colonial period in Buenos Aires. Thus, the City Administration organizes a complete guided tour around the buildings of this historical block during which, depending on the day and time, all the secrets hidden in the famous Manzana de las Luces may be discovered:
MONDAY THROUGH FRIDAY:
3pm: Façades. Old university and viceregal houses. Patio of the Jesuit Missions. Representatives Chamber. Tunnels from the 18th century.
SATURDAY:
3pm: Viceregal houses. Representatives Chamber. Chamber of the City Administration. Tunnels of the 18th century.
4.30pm: Manzana de las Luces from the outside. Tunnels from the 18th century. Optional visit with extra charge: San Ignacio Church.
6pm: Viceregal houses. Representatives Chamber. Chamber of the City Administration. Tunnels of the 18th century.
SUNDAY:
3pm: Façades. Old University. Nacional Buenos Aires School. Tunnels from the 18th century. Optional visit with extra charge : San Ignacio Church.
4.30pm: Manzana de las Luces from the outside. Tunnels from the 18th century. Optional visit with extra charge: San Ignacio Church.
6pm: Viceregal houses. Representatives Chamber. Chamber of the City Administration. Tunnels of the 18th century.
Guided tours are provided in Spanish. Under-6-year-old children do not pay the ticket. Guided tours in English must be requested 15 days in advance and require a group of, at least, 20 people. The meeting point of all guided tours is on Perú 272.
MORE INFORMATION:
For more information about Manzana de las Luces, call to the following telephone numbers: 4343-3260 / 4342-6973.