The bustling area around Largo and Rua da Carioca is filled with a maze of interesting cobblestoned streets—some of them closed to vehicles—pockets of which still capture the flavor of 19th and early 20th century Rio [1]. Largo da Carioca itself is usually packed with outdoor vendors.
From this square, you will immediately be impressed by the monumental hillside complex consisting of the Igreja de São Francisco da Penitência [2] and the Convento de Santo Antônio [3].
Links:
[1] http://www.moon.com/destinations/brazil/rio-de-janeiro/rio-de-janeiro-city
[2] http://www.moon.com/destinations/brazil/rio-de-janeiro/rio-de-janeiro-city/sights/centro/igreja-da-ordem-terceira-de-sao-francisco-da-penitencia
[3] http://www.moon.com/destinations/brazil/rio-de-janeiro/rio-de-janeiro-city/sights/centro/convento-de-santo-antonio