It has been designated as a Site of Special Scientific Interest since January 1967 in an attempt to protect its fragile geological elements.

This site is designated due to its geological quality: Robeston Wathen Quarries SSSI has one special feature: Caradoc - Ashgill (late Ordovician) sedimentary rocks in disused quarries and a stream bed.

In Wales, geological sites range from quarries to rocky outcrops and massive sea-cliffs.

[citation needed] The sedimentary rocks of impure limestones, calcareous mudstones and black mudstones have yielded a variety of fossils which include evidence that the rocks are from the Caradoc – Ashgill stages - around 440 million years ago.

The fossils also provide a means of correlation with other similar sites, and are catalogued by National Museum Wales.