natives were defeated in the 1540s. Surveys of the other surrounding hills were undertaken by Tolosa, Diego de Ibarra, Baltasar Temiño de Bañuelos, Andrés de Villanueva and others. A military mining camp was formally established in 1548 and called Minas de Nuestra Señora de Remedios. The first major vein of silver was found in 1548 in a mine called San Bernabé. This was followed by similar finds in mines called Albarrada de San Benito, Vetagrande, Pánuco and others. This brought a large number of people to Zacatecas, including craftsmen, merchants, clerics and adventurers. In 1550, royalty found its way to Zacatecas in the person of Leonor Cortés Moctezuma, the illegitimate daughter of conquistador Hernán Cortés and Isabel Moctezuma, daughter of the Aztec emperor. Doña Leonor married Juan de Tolosa. The settlement grew over the space of a few years into one of the most important cities in New Spain and the most populous after Mexico City. The camp became a parish in 1550, in 1585, then it was declared a city with the name of "Muy Noble y Leal Ciudad de Nuestra Señora de Zacatecas" (Very Noble and Loyal City of Our Lady of Zacatecas), receiving its coat of arms from Philip II of Spain at the same time. The success of the mines led to the arrival of indigenous people and the importation of black slaves to work in them. The mining camp spread southwards along the course of the Arroyo de la Plata, which now lies underneath Hidalgo Avenue, the old town's main road. Tall buildings were constructed along here due to the lack of flat area on which to build. The first house was supposedly built in 1547, just before the fortress and metal foundry. Hospitals and hospices were built in the 1550s. Zacatecas was one of the richest states in Mexico. One of the most important mines from the colonial period is the El Edén mine. It began operations in 1586 in the Cerro de la Bufa. It principally produced gold and silver with most of its production occurring in the 17th and 18th centuries. Today, the opening of this mine is within the city limits and was closed to mining in 1960. It was reopened as a tourist attraction in 1975. By the end of the 16th century, the city was the second most important, after Mexico City, and the income its mines produced for