Humboldt House (Casa Humboldt) is at Calle Juan Ruíz de Alarcón #12. It dates from the 16th century. German naturalist Baron Alexander von Humboldt spent the night in April 1803 while on a scientific journey that included South America and Cuba, hence the name. The restored house, boasting a rich Moorish facade, previously functioned as a convent, a hospital and Taxco's first movie theater. It houses the Museum of Viceregal Art (Museo de Arte Virreinal), which has a small but interesting collection of religious paintings and also hosts special art exhibits.