Rhyd Ddu is a village in Gwynedd, Wales.
It is situated within the LL54 postcode district, which is within the Caernarfon post town.
The full list of postcode districts within the Caernarfon post town is as follows:
The Caernarfon post town is within the Llandudno postcode area.
Administrative Ward: Waunfawr
Administrative District: Gwynedd
Country: Wales
UK Parliament: Arfon