List of standardised Welsh place-names
The list of standardised Welsh place-names is a list compiled by the Welsh Language Commissioner to recommend the standardisation of the spelling of Welsh place-names, particularly in the Welsh language and when multiple forms are used, although some place-names in English were also recommended to be matched with the Welsh. The list contains almost 3,500 entries, as of November 2023.
Source: Wikipedia — List of standardised Welsh place-names (CC BY-SA 4.0)