Blaen-pan-dwfn (Unclassified).
Grid Reference: SN 23931 32609. Parish: Clydau, Pembrokeshire
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website

Cae dwfn (Field).
Grid Reference: SN 47992 47835. Parish: Llanwenog, Cardiganshire
When recorded: 1841. Primary Source: none. Secondary Source: Cynefin

Cae'r Dwfn (Field).
Grid Reference: SH 62556 35557. Parish: Llandecwyn, Merionethshire
When recorded: 1841. Primary Source: none. Secondary Source: Cynefin

Careg Dwfn (Topographic feature).
Grid Reference: SN 65210 17207. Parish: Llandeilo Rural, Carmarthenshire
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website

Carreg y dwfn Hill (Topographic feature).
Grid Reference: SN 65229 17245. Parish: Llandeilo Rural, Carmarthenshire
When recorded: 1841. Primary Source: none. Secondary Source: Cynefin

Coed Careg-dwfn (Topographic feature).
Grid Reference: SN 65757 17140. Parish: Llandeilo Rural, Carmarthenshire
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website

Cwm Dwfn (Unclassified).
Grid Reference: SN 84797 96051. Parish: Penegoes, Montgomeryshire
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website

Cwm dwfnant (Field).
Grid Reference: SN 90507 43065. Parish: Penbuallt, Brecknockshire
When recorded: 1841. Primary Source: none. Secondary Source: Cynefin

Cwm Dwfnant (Unclassified).
Grid Reference: SN 89616 43645. Parish: Penbuallt, Brecknockshire
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website

Cwm-dwfn (Unclassified).
Grid Reference: SO 24976 09685. Parish: Blaenavon, Monmouthshire
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website