[Nant] Cyrnach (Topographic feature).
Grid Reference: SN 71365 00573. Parish: Ynys-y-mond, Glamorgan
When recorded: 1699. Primary Source: Parochialia 3. Secondary Source: none

Blaen-Cyrnog (Settlement).
Grid Reference: SN 90500 39885. Parish: Llandeilo'r-Fan, Brecknockshire
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website

Cae cyrn bach (Field).
Grid Reference: SS 61694 94140. Parish: Swansea, Glamorgan
When recorded: Circa 1840. Primary Source: none. Secondary Source: Cynefin

Cefn-Cyrnog (Unclassified).
Grid Reference: SN 90074 38061. Parish: Llandeilo'r-Fan, Brecknockshire
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website

Coed Nant Cyrniog (Unclassified).
Grid Reference: SH 87668 13074. Parish: Mallwyd, Merionethshire
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website

Cwm Cyrnog (Unclassified).
Grid Reference: SN 90267 38761. Parish: Llandeilo'r-Fan, Brecknockshire
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website

Cwm-cyrnach -uchaf (Unclassified).
Grid Reference: SN 71475 00686. Parish: Ynys-y-mond, Glamorgan
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website

Cwm-deri-cyrn (Settlement).
Grid Reference: SN 54340 07901. Parish: Llannon, Carmarthenshire
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website

Cyrnau (Unclassified).
Grid Reference: SN 72949 53404. Parish: Llanddewi-Brefi, Cardiganshire
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website

Cyrnau (Unclassified).
Grid Reference: ST 05536 92546. Parish: Pontypridd, Glamorgan
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website