Smarts Quarry is a Site of Special Scientific Interest (SSSI) in Carmarthenshire, Wales, designated in 1987 for its geological features.

[1][2] Smarts Quarry SSSI is located approximately 0.5 miles (0.80 km) east-north-east of Mynydd-y-Garreg, and covers 2.6 hectares (6.4 acres).

[1][2] The SSSI citation for Smart Quarry specifies the importance of "abundant, bivalve produced, stellate feeding traces on a bedding surface" within the Namurian quartzite of the quarry.

The citation finds such traces unique within the Namurian basal grits of South Wales and suggestive of an estuarine rather than a shoreline sedimentary deposition of the quarry stone.

[2]