Instituto Saturnino Unzué, Neo-Byzantine former orphanage in Mar del Plata, Argentina

Instituto Saturnino Unzué is a Neo-Byzantine building in Mar del Plata, built from 1910 for the Unzué sisters as an orphanage. Its H-shaped plan develops over two levels, and the interiors are lined with Abisinia, Carrara and Proconeso marble. Inside stands the Oratorio de la Inmaculada Concepción, inaugurated on 5 March 1912, whose dome measures about 10 metres in diameter.

The Unzué sisters, Concepción Unzué de Casares and María de los Remedios Unzué de Alvear, commissioned the building in 1910 from French architect Louis Faure-Dujarric, with Mauricio Cremonte as builder. In 1911 they donated it to the national state in memory of their father, Saturnino Unzué. Extensions followed between 1913 and 1927, and the whole building was declared a National Historic Monument on 16 May 1997.

The Oratory of the Immaculate Conception, inside the building, was inaugurated on 5 March 1912. Its dome, about 10 metres across, is pyramidal with three arches, a small barrel vault and a bell-tower finish with a spire. The interior is lined with Abisinia, Carrara and Proconeso marble.

Programs at the Unzué ceased in March 2025, when the state dismissed all its workers and the building's future remained undecided; councillors have since proposed uses such as a shopping centre. The exterior and the Oratory can be seen from the street, but the interior is closed and without use, so visits depend on a decision by the national ministry.

The pulpit won the first international design prize awarded in Seville in 1910. The Pantocrator inside resembles the figure in the Hagia Sophia cathedral in Istanbul, a detail visitors can compare with photographs of the original.