I cross-posted:
Like English, however, whatever the "purists" may tell you, there are local variations in place name pronunciation although not as marked as in English. When I lived in Aberystwyth the locals would make fun of the "Oxford Welsh" who pronounced the town's name in the "corect" phonetic manner.
Aberystwyth: commonly pronounced A (as in hat) ber (as in the natural 'burr') ist with ('th' soft as in 'pith', not hard as in 'with')
For purists, the third syllable should be 'ust' (as in 'lust').
For 'would be taffies' from Cardiff, Aber-wrist-watch' is close enough!

Also, despite 'received wisdom' that the accent is (nearly) always on the penultimate syllable, the word is a combination of 'Aber' (mouth of a river) & 'Ystwyth' (name of a river) so accent should be on both 'A' (of Aber) And 'Yst' of Ystwyth. (I am open to correction by those more knowledgable)

Cheers

Nigel