The Monadnocks

A monadnock is an isolated hill, typically found in temperate regions, that stands above a lower-lying plain. Because a monadnock is made of hard igneous or metamorphic rock, such as granite or quartzite, it remains as a conspicuous, solitary landform while the surrounding area erodes away at a faster rate.

Georgia’s three primary monadnocks, Arabia, Panola, and Stone Mountains, are home to many rare plants and animals, such as pool sprite and fairy shrimp.

Georgia's Physical Features

Dominating the skyline just northeast of Atlanta, Stone Mountain’s 7.5-billion cubic feet of rock is the largest mass of exposed granite in the world. Due to its harsh natural environment, Stone Mountain plays host to a variety of hearty plants and animals, including the endangered clam shrimp. Formed more than 300 million years ago, the mountain’s visibility has made it an important landmark for as long as humans have inhabited the area.

The carving on Stone Mountain took nearly 50 years to complete and is the largest high-relief sculpture in the world. Depicted are Jefferson Davis, Robert E. Lee, and Thomas “Stonewall” Jackson.

The Summit Skyride carries visitors in a Swiss cable car to the top of Stone Mountain, looming 825 feet above the surrounding park. Hikers may also climb the one-mile trail to experience the spectacular views from the mountaintop.​

The Stone Mountain Natural District features a historic grist mill, originally built in 1867, with a reconstructed waterwheel. The abandoned mill was moved to the park in 1965 from Fannin County.​​

The Stone Mountain daisy (Helianthus porteri) blooms brilliantly in September, growing in rock crevices and wooded areas throughout the mountain.​

Although Panola Mountain gives an initially stark impression, it is surrounded by acres of deciduous forests that burst into color during the autumn months, and its unique ecosystems shelter many colorful organisms, such as red elf orpine and yellow sunnybell.

The exposed granite surface of Panola Mountain and other similar monadnocks is often characterized by flat “pavement rock” dotted with erosion-resistant boulders. Soil accumulation is rare because rainfall washes organic materials and weathered rock fragments down the slopes of the domed outcrop.

A 170-foot tall monadnock, or “moonscape rock,” rising out of a layer of trees, Arabia Mountain was donated to DeKalb County in the 1970s. In 2006, Congress designated the monadnock and its surrounding 40,000 acres as the Arabia Mountain National Heritage Area.

Famous for its Lithonia Tidal Grey granite, which was quarried for landmarks like the Brooklyn Bridge and countless buildings throughout the country, miners have been coming to Arabia Mountain since before Reconstruction to hand-cut blocks of stone.

The wider Heritage Area is home to five endangered plants, a community of Trappist monks, and perhaps DeKalb County's oldest African-American community of Flat Rock.

Hikers on Arabia Mountain are guided by cairns, or hand-stacked piles of rocks.

Small’s stonecrop (Diamorpha smallii) is a rare succulent plant that grows primarily in Georgia and is found on both Arabia and Panola Mountains. Once a year, it turns from green to bright red before blossoming into tiny white flowers.