When I've been to Brazil I've visited 3 of the 4 UNESCO sites in Minas Gerais state, Diamantina, where this card is from, was the only one I didn't get to visit because it was too far from the places I was staying.
The card was sent by Luzia.
The Church of Our Lady of the Rosary of the Blacks, was built in 1731 by the Brotherhood with the same name. It is one of the oldest temples of Diamantina. It has a simple facade, however, it keeps an altar clad in gold.