Belfast to Dublin, Shannon to London?

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I cannot seem to book a train ticket from Belfast to Dublin online. I get an error message that says you cannot book from Northern Ireland to Southern. Should I just book the ticket on the spot when I'm there in August? Do trains run regularly? Also, is it possible to get from Shannon to London by ferry and train without having to fly?
Thanks,
Gypsy

Travel Tips

You don't need to book trains from Belfast to Dublin in advance. There is always a seat. I presume you realise that Belfast is under British rule and Dublin is in the Irish Republic. Also Belfast uses sterling and Dublin uses EurosThe trains are modern fast and safe and the views are specacular. If you must get from Shannon to London it is very tedious by coach. You get on at Limerick which is 15 miles from Shannon about 6pm and [usually] route via Dublin, Holyhead in Wales, Liverpool and eventually arrive in London about 7am, SHATTERED. You can fly from Shannon to various London airoprts for buttons in about an hour. Source(s): I worked in Shannon fof 25 years and grew up in Dublin

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