[2] The area is due east of Atlanta and spans 40,000 acres (16,000 ha) reaching from the historic commercial center of Lithonia to the Monastery of the Holy Spirit in Conyers, including several sites in between, including Panola Mountain, Davidson-Arabia Mountain Nature Preserve, and the historic Flat Rock Community with the Flat Rock Archives.

Davidson-Arabia Mountain Nature Preserve includes 2,550 acres with a multi-use bike path, hiking trails, and lakes for fishing.

[4] The existence of the Atlanta Augusta Railroad allowed the granite quarry industry in the area to flourish in the late 1800s.

The stone quarried from Arabia Mountain, officially called "Tidal Grey", was prized for its high structural density and compressive strength as well as its "swirl" pattern.

[13] Another advancement to the quarrying industry at Arabia Mountain was the discovery that adding granite grit to chicken feed helped with the birds' digestion.

The Davidson family, which owned several quarries in the area, became the largest supplier of poultry grit in the world.

They claimed that the sparkling particles of mica in the Stonemo grit attracted the eye and helped the chicken's gizzard break down food.

The company was so successful in distributing their feed additive, a Time magazine article from 1941 reported the U.S. government allowed them to continue to operate during World War 2 in the name of national defense.

In the 1970s, the Davidson family donated over 500 acres including Arabia Mountain and surrounding lands to DeKalb County as a nature preserve for local residents to enjoy.

[citation needed] The Arabia Mountain purchase was initiated by DeKalb County Chief Executive Officer Vernon Jones.

The Jones administration continued its efforts and collaborated with Congresswoman Denise Majette, Congressman Jack Kingston, and Senator Saxsby Chambliss in passage in both houses federal legislation authorizing and declaring Arabia Mountain a national heritage area.

For example, Arabia Mountain features a unique "swirl" pattern because the heat and pressure caused the rock to have a taffy-like consistency when it was cooling over 400 million years ago.

Although made of metamorphic rock, the mountain is actually composed of migmatite, metamorphosed at higher temperatures than gneiss but not sufficiently melted to become granite.

Over time, these depressions fill with sand washed down from higher locations, which accumulates a small amount of organic content from decaying dead leaves and other detritus, as well as rain water.

This allowed shallow amounts of soil to accumulate, providing a place for more plant life to take root.

[23] Not only does plant matter such as moss erode the rock and help to build soil levels in the pits, but the stone is also weathered by non-chemical factors.

Cracks can form, giving another foothold to plant life, and the rock is broken into particles that add to the shallow soil.