I am not sure this sentence is appropriate. I am a fluent Welsh speaker and it threw me. Someone who does not know the geography of Wales would have no chance
This skill is a bit odd. A few Welsh place names would get the point across, the rest could be replaced with countries as those are more memorable and perhaps more useful than a selection of random town names.
I would say truly odd. Country names or more generic places would be useful. Something like "I work in the city" or "I am swimming in the lake"
Oh, how is breaks my heart that my hometown is simply too obscure for both learners and Welsh speakers alike!
there is a section where it tells you the place names they test you on in the notes
Personally, I think we should leave a form of this question in the course (I am bias of course, being an Aber man myself.), but it could be changed to something more, how should I say, culturally appropriate?
My suggestion: 'Dych chi'n bwyta caws yn Y Fenni'? Why? Because, us Monmouthshire types are not only quite fond of our cheeses, but we're also known for our 'Y Fenni' cheese, made from mustard seeds and ale! Highly recommended.
Is 'Y Fenni' a familiar name for Abergavenny, along similar lines to Pompey for Portsmouth?
I was born there and raised in a village nearby. It is, like you assumed, a Welsh language shortening. The older form (which is still the more prominent usage by English speakers and Welsh speakers alike) IS Abergavenny: Aber (mouth of) Gafenni (river Gavenny).