Town hall representatives in the Valencian municipality of Vilafranca announced the finding on Tuesday, the first of its kind and importance for many years in the region.
Although archaeologists are still searching the area for more rock paintings, their work has already unveiled detailed depictions of prehistoric hunting; including bulls, goats and archers chasing them down.
The site’s location is being kept a secret until the necessary security precautions are in place.
Last April, a 5,000 year-old rock painting in southern Spain was destroyed by thieves who tried to steal the Unesco World Heritage-listed artwork by chipping it off the cave wall where it was housed.
There are several hundred sites along Spain's Mediterranean seaboard where prehistoric paintings have been found, the largest group in Europe according to Unesco.
"A lot of these places are abandoned and need greater supervision," Fae president José Antonio Berrocal told The Local.
"Although there is legislation protecting these sites in theory, there is a lack of political will," he added.
"Obviously you can't have policemen stationed in every cave, but we need a system of continuous monitoring with officers coming around periodically to monitor the situation," the cave expert explained.
"In some cases, closing off those caves may be the only option to protect world heritage paintings," he added.
The Spanish rock sites display "a critical phase of human development...in paintings whose style and subject matter are unique," Unesco says on its website.