The site was found at Mount Cimino near Viterbo, 50 miles north of Rome, ANSA news agency reported Tuesday.
Archaeologists led by Professor Andrea Cardarelli of La Sapienza University in Rome have carried out excavations on the 3,200-foot summit for the past three years.
A number of materials were linked to cult fires and "clear evidence of votive offerings," Cardarelli said.
"Religious activities 1,000 years B.C. were carried out through fire," he said. "Offerings were burnt for the gods -- sacred objects, food or animals."
The discovery is said to be one of the most important in the early history of Lazio, the region surrounding Rome, with archaeological remnants dating back to 1000 B.C. and the Bronze Age.