Cefn Mawr, meaning great ridge in English, is situated near the south west boundary of Wrexham and Denbighshire. Cefn Mawr is situated between Ruabon and Llangollen, approximately 7 miles from Wrexham. The village is located on a steep- sided, sandstone outcrop almost 100 metres above the Dee Valley floor and marks the eastern gateway to the Vale of Llangollen.
The conservation area encompasses the historic core which has been formed on several tiers within the hillside, wrapped around a central quarry creating a unique and distinctive townscape. Its elevated position affords Cefn Mawr with magnificent views along the Vale of Llangollen towards the Pontcysyllte Aqueduct, which was inscribed a UNESCO World Heritage Site in June 2009.
The Cefn Mawr conservation area was designated in November 2004. The Cefn Mawr Conservation article 4(2) direction came into effect in January 2006. The Cefn Mawr Conservation Area Character Assessment and Management Plan was adopted in September 2012.