I'm quite interested in the idea of Celtic languages - Irish, Manx, Scottish Gaelic, also Welsh, Cornish, Breton etc being spoken in towns & cities as opposed to rural areas. "Urban Celts", as it were.

A good example would be #Llanelli in the south of Wales...

My understanding is that in the mid-20th century, Llanelli was the largest town in the whole world where more than half the population spoke a Celtic language.

The town (now city) of #Inverness was also maj. #Gàidhlig speaking until about the mid 19th century

I am less sure however about Ireland, due to my own lack of knowledge, but I would wonder about places like Limerick, Cork & Waterford (the towns rather than counties). Do we know roughly when they lost their Irish speaking majorities?