In 1912, the Basilica del Santisimo Sacramento was opened to the public; its construction was funded by the generous donation of Argentine philanthropist Mercedes Castellanos de Anchorena, a member of Argentina's most prominent family. The church is an excellent example of French neo-classicism. With extremely high-grade decorations in its interior, the magnificent Mutin-Cavaillé coll organ (the biggest ever installed in an Argentine church with more than four thousand tubes and four manuals) presided the nave. The altar is full of marble, and was the biggest ever built in South America at that time.