You would drive to one of the ferry ports in Wales or England and get a ferry to Ireland. You can go from Fishguard to Rosslare, Holyhead to Dún Laoghaire or Liverpool to Dublin.
to visit Blarney for the day you could travel by car on the M7 and M8 motorway - about 2.5 hours from the limit of Dublin or you could travel by train from Dublin Heuston to Cork and travel to Blarney from the station - about 3.5 hours
It is cheaper to fly from London to Dublin than to rent a car in London and drive (and catch a ferry across the Irish sea) to Dublin. If you shop around you can get some very good value air fairs from London to Dublin.
What is travel time from Boston MA to Montreal by car?
There are no car ferries between Ireland and London. You must firstly establish from which part of Ireland you are travelling from and get to the nearest ferry port. Possible options are Cork, Rosslare, Dún Laoghaire, Dublin or Larne. Depending on which of these you travel from will depend on which ports you could go to in Britain. When you arrive in Britain, you will then have to drive to London which will be at least 150 miles and possibly more. Holyhead or Fishguard, both in Wales, are the best options to go to.
FRANKFURT, DEUTSCHLAND to CHERBOURG, FRANCE (989 kilometres):Take A5 BASEL from Frankfurt to A67 to MANNHEIM.Take A67 to A6 to SAARBRÜCKEN.Take A6 to FRANCE, where it becomes A320.Continue on A320 to A4 (péage [toll]) to METZ-PARIS.Take A4 to A26 (péage) to CALAIS.Take A26 to A29 (péage) to AMIENS.Take A29 to A31 (péage) to CAEN.Take A31 to N13 to CHERBOURG via the PÉRIPHÉRIQUE SUDaround CAEN.Take N13 to CHERBOURG; FOLLOW SIGNS to the CAR FERRIES.Take a FERRY from CHERBOURG, FRANCE to ROSSLARE, IRELAND. The ferry is operated by the IRISH FERRIES company. The crossing is about 16 hours long.ROSSLARE to DUBLIN (156 kilometres):From Rosslare Harbour, follow N25 to N11 to DUBLIN in Wexford, and then take N11 to DUBLIN.
Dublin car rentals in Ireland do offer the occasional rental deals. You can also find coupon codes online if you want to reserve a car ahead of time and pick it up at the airport.
On the Avis website one can go online to find information on car rentals in Dublin and Car Hire 3000 also offers information on car rentals in Dublin.
Car hiring should not be a problem in Dublin. It being in Europe, there should be many car rental companies that allow you to rent. Also many of the rental companies in US has there branches in Dublin.
Take a flight from any of London's 4 airports. British Airways, Aer Lingus, bmi, EasyJet, Ryanair and others all fly to Dublin. Takes about an hour. Or, much less convenient but prettier, drive from London to Holyhead in Wales and take a ferry to Dublin. The drive is around 4 hours, the ferry around 3.
"There are actually quite a few! Believe it or not, Usually Car rentals in Dublin are very inexpensive as well. Although, I would suggest not renting a car because Dublin traffic is usually very congested."
There are many highly rated agencies for car rentals in Dublin. These include, but are not limited to, Thrifty Rent a Car, Argus Car Rentals, and Breeze Rent a Car.