Despite of the fact that the aboriginal population called it Huelén, that in Mapudungun language means "Pain, melancholy or sadness", its current name comes from the day in which Pedro de Valdivia took possession of the hill, on 13 December, day that remembers to  Santa Lucía.

Santa Lucia Hill - Santiago

Panoramic View 360, Source[Level Second] of Santa Lucia Hill

When the conquerors arrived to the Mapocho’s river valley, they used this large crag as a lookout.
During the reconquest ( 1814-1817 ), the general Casimiro Marcó del Pont (last Spanish governor of the General Captainship of Chile), made to build two defensive batteries in 1820: the Marco and the Hidalgo castle.
The SantaLucía hill is the place where Pedro de Valdivia founded the City of Santiago de Nueva Extremadura on February 12, 1541.

Source: Wikipedia.org

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