List of Sites of Special Scientific Interest in Brecknock

This is a list of the Sites of Special Scientific Interest (SSSIs) in the Brecknock Area of Search. For SSSIs elsewhere in Wales, see List of SSSIs by Area of Search.

* Abercriban Quarries
* Afon Irfon
* Afon Llynfi
* Afon Wysg (Isafonydd) / River Usk (Tributaries)
* Alexanderstone Meadows
* Allt Cynhelyg
* Allt-y-gest
* Baltic and Tyle'r-bont Quarries
* Black Mountains
* Blaen Cilieni
* Blaen Nedd
* Boxbush Meadows
* Brechfa Pool
* Brecon Beacons
* Bryn-bwch
* Buckland Coach House & Ice House
* Cae Bryn-tywarch
* Cae Comin Coch
* Cae Gwernllertai
* Cae Llety-yr-efail
* Cae Penmaes
* Cae Pwll-y-bo
* Caeau Blaen-bydernyn
* Caeau Bronydd-mawr
* Caeau Cnwch a Ty'n-y-graig
* Caeau Cwmcoynant (Caeau Cwncaenant)
* Caeau Fferm
* Caeau Llwyn Gwrgan
* Caeau Nant y Llechau
* Caeau Ton-y-fildre
* Caeau Ty-mawr
* Caeau Ty'n-llwyni
* Carn Gafallt
* Cathedine Common Wood
* Coed Blaen-y-cwm (Blaen-y-cwm Wood)
* Coed Dyrysiog
* Coed Mawr - Blaen-Car
* Coed Nant Menascin
* Coed y Ciliau
* Coed Ynys-Faen
* Craig y Rhiwarth
* Cwar yr Ystrad a Cwar Blaen dyffryn
* Cwm Craig-ddu Quarry
* Drostre Bank
* Duhonw
* Dyffrynoedd Nedd a Mellte a Moel Penderyn
* Erwood Dingle
* Garth Bank Quarry
* Gweunydd Dyffryn Nedd
* Gyfartha
* Halfway Quarry
* Hen-allt Common
* Heol Senni Quarry
* Illtyd Pools
* Llangammarch Wells Quarry
* Llofft-y-bardd
* Llwyn-Cus
* Llyn Syfaddan (Llangorse Lake)
* Mwyngloddfa Nantiago
* Mynydd Epynt
* Mynydd Llangatwg (Mynydd Llangattock)
* Nant Clydach Pastures
* Nant Llech
* Nant y Rhos
* Neuadd and Tylelo Mires
* Ogof Ffynnon Ddu
* Ogof Ffynnon Ddu-Pant Mawr
* Penllwyn-yr-Hendy
* Pentregwyn
* Pen-yr-hen-Allt
* Plas-y-Gors
* Pwll-y-wrach
* Rhagnentydd Gwy Uchaf / Upper Wye Tributaries
* Rhos Garth-fawr
* Rhos Hen-Glyn-Isaf
* Rhosydd Llanwrthwl
* River Usk (Upper Usk) / Afon Wysg (Wysg Uchaf)
* River Wye (Upper Wye) / Afon Gwy (Gwy Uchaf)
* Talybont Reservoir
* Tyncoed Pasture
* Upper Chapel Pastures
* Vicarage Meadows
* Waen Rydd
* Waun Ton-y-spyddaden
* Y Gors