Caeau Pen-y-coed is a Site of Special Scientific Interest in the preserved county of Clwyd, north Wales.
Chwarel Singret is a Site of Special Scientific Interest in the preserved county of Clwyd, north Wales.
Cil-y-groeslwyd Woods, Eyarth Woods & Rocks & Craig Adwy-wynt is a Site of Special Scientific Interest in the preserved county of Clwyd, north Wales.
Coed y Gopa is a Site of Special Scientific Interest in the preserved county of Clwyd, north Wales.
Connah's Quay Ponds and Woodland is a Site of Special Scientific Interest in the preserved county of Clwyd, north Wales.
Crest Mawr Wood is a Site of Special Scientific Interest in the preserved county of Clwyd, north Wales.
Graig Fawr is a Site of Special Scientific Interest in the preserved county of Clwyd, north Wales, now in Denbighshire. It is 153 metres high and located near Prestatyn. It is owned by the National Trust.
Graig Quarry is a Site of Special Scientific Interest in the preserved county of Clwyd, north Wales.
Graig, Llanarmon-yn-Ial is a Site of Special Scientific Interest in the preserved county of Clwyd, north Wales.
Hanmer Mere is a Site of Special Scientific Interest in the preserved county of Clwyd, north Wales, now in Wrexham county borough.
Hendre Bach is a Site of Special Scientific Interest in the preserved county of Clwyd, north Wales.
Hendre, Llangedwyn is a Site of Special Scientific Interest in the preserved county of Clwyd, north Wales.
Llanddulas Limestone and Gwrych Castle Wood is a Site of Special Scientific Interest in the preserved county of Clwyd, north Wales. The designated area lies in the communities of Betws yn Rhos, Llanddulas and Rhyd-y-foel and Llysfaen. The hills of Cefn-yr-Ogof and Craig y Forwyn feature. Gwrych Castle Wood is part of Gwrych Castle, a privately owned estate.
Llwyn is a Site of Special Scientific Interest in the preserved county of Clwyd, north Wales.
Llyn Ty'n y Llyn is a Site of Special Scientific Interest in the preserved county of Clwyd, north Wales.
Maes Hiraddug is a Site of Special Scientific Interest in the preserved county of Clwyd, north Wales.
Nant-y-Belan and Prynela Woods is a Site of Special Scientific Interest in the preserved county of Clwyd, north Wales.
Pen-y-Cefn Pasture is a Site of Special Scientific Interest in Cilcain, Flintshire, in the preserved county of Clwyd, north Wales. It has been an SSSI since 10 December 1986 as a conservation attempt to protect and preserve the site. Its area is 2.35 hectares. Natural Resources Wales is the body responsible for the site.
Marford Quarry is a quarry and a Site of Special Scientific Interest in the preserved county of Clwyd, north Wales. It is managed by the North Wales Wildlife Trust.
