Santa Cruz de Oñez was a fort founded by Martín García Oñez de Loyola

Martín García Óñez de Loyola

Don Martín García Óñez de Loyola was a Spanish Basque soldier and Royal Governor of Chile.-Early life:...

 in May of 1594, near the confluence of the Bio-Bio and Laja River

Laja River (Chile)

Laja River is a river in Chile, along which can be found the Laja Falls. It is located in the Bío-Bío Region. The source of the river is Laguna del Laja in the Andes, then flows westward through the Chilean Central Valley and terminates into the Bío-Bío River, being an important tributary of...

s on the right bank of the upper reach of the Rele River

Rele River

Rele River is a river in the commune of Santa Juana. It has its origin to the south southeast of Santa Juana, from where it runs to the northeast from among the slopes of the heights of the Nahuelbuta Range and runs to the east to the Bio Bio River in which it empties a little above the confluence...

 in Catiray, ten kilometers south of the Bio Bio. The site was in an elevated location but with a shortage of water. Gold mines were located across the Rele on a stream called Millapoa.

The fort was elevated to the rank of city in 1595 giving it the name of Santa Cruz de Coya

Santa Cruz de Coya

Santa Cruz de Coya was a city established by the governor of Chile Martín García Oñez de Loyola on the site of the fort of Santa Cruz de Oñez, in 1595. It was named for his wife Beatriz Clara Coya, a member of the royal Incan house...

, or Millacoya.

Source

• Atlas de Historia de Chile, Editorial Universitaria, ISBN:9561117762 pg. 48.
• Francisco Solano Asta-Buruaga y Cienfuegos, Diccionario geográfico de la República de Chile, SEGUNDA EDICIÓN CORREGIDA Y AUMENTADA, NUEVA YORK, D. APPLETON Y COMPAÑÍA. 1899. Pg. 190 Coya