 In the apse at the east end is a mosaic of Our Lady of Sorrows by Giambattista Conti and a high altar decorated with onyx and covered by a baldachino supported by four granite Corinthian columns.The choir is separated from the nave by an altar ring of white marble which includes intaglia and bronze gates with the national coat-of-arms and the arms of the Order of the Mercedarians.At one altar is a small statue of Our Lady of Luján, principal patron of Argentina.