| Cantre'r Gwaelod The Lowland Hundred | |
|---|---|
| Welsh mythology location | |
 Part of an ancient submerged forest at Ynyslas thought to be associated with Cantre'r Gwaelod | |
| Genre | Legend |
| In-universe information | |
| Type | Sunken kingdom |
| Locations | Caer Wyddno |
| Characters | |
Cantre'r Gwaelod, also known as Cantref Gwaelod or Cantref y Gwaelod (Welsh for 'The Lowland Hundred'), is a legendary ancient sunken kingdom said to have occupied a tract of fertile land lying between Ramsey Island and Bardsey Island in what is now Cardigan Bay to the west of Wales. It has been described as a "Welsh Atlantis" and has featured in folklore, literature, and song.