That will depend on your own nationality and where you are initially travelling from. Contact your department of foreign affairs, or the Irish one for more information.
It's 356 miles from Cardiff to Dublin
no, as long as you have a passport
no you dont
You need a passport to enter any country, that's why you have passport control at airports.
Cardiff is in Wales. Dublin is in Ireland. Edinburgh is in Scotland. London is in England.
yes. which ever way you leave a country, u need a passport
Yes you would need a passport. You would also need a visa.
definitely, yes
As the "Common Travel Area" is in place, you do not need a passport to go to Dublin from the UK. When flying between the UK and Ireland it is best to ask your airline what form of ID will be accepted.
Dublin
That will depend on various factors, like your nationality and what your requirements are for getting to England.
No, you do not need a passport to fly from Anglesey to Cardiff, as both locations are within the UK. Domestic flights in the UK typically do not require passengers to present a passport; however, a form of identification may be needed. It's advisable to check with the airline for their specific requirements.