About 100 ancient "cult sites" decorated with penis statues and vulva-shaped relics have been uncovered in Israel's Negev Desert, according to Live Science.

The prehistoric sites date back 8,000 years and feature stone circles measuring 1.5 to 2.5 meters across (about 5 to 8 feet) with penis-shaped fixtures pointing toward them, human shapes made of stone and stone bowls.

Of the 100 sites, many are grouped together, like one area that has 44 sites in only 0.8 square kilometers (less than 200 acres). "Taking in[to] consideration the topography, environmental conditions and the small number of known Neolithic habitations in the general southern Negev, the density of cult sites in this region is phenomenal," the archeologists wrote in an article published by Journal of the Israel Prehistoric Society, according to Live Science.

Judging by the bones found at the sites, the team surmises that animal sacrifice was part of the rituals performed.

Fertility and death are the most common themes represented. The team found penis-shaped stone structures pointing toward vulva-shaped holes. "The circle is a female symbol, and the elongated cell is a male one (phallus)," Uzi Avner, a researcher with the Arava-Dead Sea Science Center and the Arava Institute, wrote in an email to Live Science.

Death is "signified by the burial of stone objects and by setting them upside down," the team members wrote in their paper, according to Live Science.

"Combinations of both (fertility and death) are actually well-known in anthropological studies as relating to ancestral cult," the archaeologists wrote.

Avner told Live Science that a "survey of a larger area yielded to date 349 cult sites."

"The number of cult sites recorded to date suggests that many more still await discovery," the researchers wrote, according to Live Science. "Many more may be found on the mountains of the Negev, southern Jordan and Sinai."