The area includes the Hoya de Baza and the valleys of the Galera, Huescar and Guardal rivers.
Approximately 8 million years ago the altiplano is thought to have formed a huge inlet that connected the Atlantic and the Mediterranean Sea.
As the mountain building activity associated with the Sierra Nevada has raised the area, so the level of the sea fell and temporarily formed an inland lake, eventually the area drained to the east, towards the Rio Guadalquivir.
The geology of the altiplano is characterised by naturally cemented horizontally arranged oceanic sediments.
[1] Climate Rainfall in the basin is slight, but precipitation falls on the surrounding mountains and spawns a number of Rivers