When English people pronounce:

Betws-y-Coed as "Betsy Coe-Ed"
Llanelli as "Lanelly" or (if they're trying really hard) "Clanecly"
Machynlleth as "Merk eye-un luth"
Bangor as "Banger"
Heddlu as "Head Loo"
Araf as "A raff"

More to come.