| Localité | Code postal |
|---|---|
| Aber Cywarch, Gwynedd | SY20 9AF |
| Aberangell, Gwynedd | SY20 |
| Aberdaron, Gwynedd | LL53 |
| Aberdesach, Gwynedd | LL54 |
| Aberdovey, Gwynedd | LL35 |
| Abererch, Gwynedd | LL53 |
| Abergeirw, Gwynedd | LL40 |
| Abergwyngregyn, Gwynedd | LL33 |
| Abergynolwyn, Gwynedd | LL36 |
| Aberllefenni, Gwynedd | SY20 |
| Abersoch, Gwynedd | LL53 |
| Afonwen, Gwynedd | LL53 6TZ |
| Anelog, Gwynedd | LL53 8BT |
| Arenig, Gwynedd | LL23 |
| Arthog, Gwynedd | LL39 |
| Bala, Gwynedd | LL23 |
| Bangor, Gwynedd | LL57 |
| Bardsey Island, Gwynedd | LL53 8DE |
| Barmouth, Gwynedd | LL42 |
| Beddgelert, Gwynedd | LL55 |
| Belle Vue, Gwynedd | LL41 4NU |
| Bethania, Gwynedd | LL41 |
| Bethel, Gwynedd | LL55 |
| Bethel (Bala), Gwynedd | LL23 |
| Bethesda, Gwynedd | LL57 |
| Bethesda Bach, Gwynedd | LL54 |