[Avon] Yr Oerva (Topographic feature).
Grid Reference: SH 68128 40837. Parish: Maentwrog, Merionethshire
When recorded: 1699. Primary Source: Parochialia 2. Secondary Source: none

Aber-grugoer (Unclassified).
Grid Reference: SH 81315 68183. Parish: Eglwysbach, Denbighshire
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website

Aber-oer (Unclassified).
Grid Reference: SJ 28478 49294. Parish: Esclusham Above, Denbighshire
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website

Aber-oer (Unclassified).
Grid Reference: SJ 28776 49013. Parish: Esclusham Above, Denbighshire
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website

Afon Oernant (Unclassified).
Grid Reference: SH 79361 48057. Parish: Penmachno, Caernarfonshire
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website

Allt Oernant (Unclassified).
Grid Reference: SN 42822 60414. Parish: Llanarth, Cardiganshire
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website

Benchoer (Unclassified). Variant of head-name Bangor / Bangor
Grid Reference: SH 58000 72000. Parish: Bangor, Caernarfonshire
When recorded: 634 (9th cent). Primary Source: none. Secondary Source: DPNW

Blaenoerde (Unclassified).
Grid Reference: SO 21805 51917. Parish: Colva, Radnorshire
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website

Bryn Oer Tramway (Unclassified).
Grid Reference: SO 10853 21588. Parish: Llanddetty, Brecknockshire
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website

BRYN OER TRAMWAY (DISUSED) (Unclassified).
Grid Reference: SO 09286 15737. Parish: Llanddetty, Brecknockshire
When recorded: 1898-1908. Primary Source: OS 2nd Edition Maps. Secondary Source: GB1900 website