My 10 year brick wall :O(

[pierce-brosnan]

Wow Tony,

Thanks for all your hard work.  I will keep an open mind as you say and see what comes up.  If I find anything I'll let you know 

Thanks & best wishes Vanda

[Chasing-fireflies]

Obviously some English person or non welsh person has written the pronounced 'ydd' as 'with' so i would say you need to be looking at something like that.
Llanwyddelan sounds a good match but i would say there are probably plenty more welsh places that fit the bill for this one.
Could it actually be a mis pronunciation of Llandudno or llangeitho(as Falkryn pointed out)?
 

[pierce-brosnan]

Thanks bad girl