The town of Gerena is built on a granite massif, an intrusive mass that also emerges in the lands located to the north of the urban area and is part of the great plutonic mass of Castilblanco de los Arroyos.
The granite quarrying activity has given rise to the site of Las Canteras, located in El Baldío, to the east of the town of Gerena. When quarrying ended, the area was rehabilitated and paths and a viewpoint were built for people to enjoy this landscape created by what was once the main economic activity of the municipality. In the vicinity of Las Canteras is the Fuente Santa, formerly used by the quarrymen, in a resting place on a royal stock-route, among ancient eucalyptus trees. It is a square built in a high area of the town from which there are wonderful views of a large part of the town, the quarries and the Sevillian countryside.