I travel Belfast to Dublin EVERY DAY to work - a motorway straight there.

I would recommend that you turn off the motorway at NEWRY and take the coastal route through WARRENPOINT, KILKEEL, through to NEWCASTLE (This take you around the STUNNING Mourne Mountains - a beautiful drive)

Through Newcastle go to DOWNPATRICK (St Patrick BURIAL GRAVE at Cathedral) - then towards STRANGFORD where you get a 5 minute ferry to PORTAFERRY. Then take the inner coastal route up towards NEWTOWNARDS - the BELFAST

A Good 5 Hour journey in total - but just beautiful.

(Reverse journey if necessary)

I would totally agree with Ardara1. That suggestion is a beautiful drive. I hope you have sunny weather for it.

I agree with the other posters on the suggested route but another route would take you to Carlingford. You really shouldn't miss this lovely town (www.carlingford.ie/).

Oh, the pain of choice!

Depending on what else you have on your itinerary, Monasterboice (High Crosses) and Newgrange are also a short detour off your route. They are nearer the Dublin side though so you may be able to include these on a daytrip from Dublin

Yes, definitely include Monasterboice. There is probably the most beautiful high cross you can see in Ireland (before it weathers away completely, does anybody look after these incredible artefacts?). Muiredach's Cross is one of the wonders in Ireland. If you're a cat lover you will like the carvings of cats at the bottom of the cross. Enjoy before it's gone. Please read the Old Irish inscription on the cross, it means "Say a prayer for Muiredach who had this cross made". Just sit and enjoy this site (not too many tourists). It really is a special place.

There is so much to see between the two cities that you could actually spend a week making your way there. What do YOU like to see? What are YOUR interests? If you love gardens then you should not miss Mount Stewart. If you hate gardens then give it a miss.

Newgrange is very interesting but it can easily eat up 4 hours or more to see it all.

Carlingford is lovely but I would think of it as a destination to stay at and enjoy, not a drive through must see.

We recently covered the route given by Ardara1, plus a detour into the Mourne mountains. And it was a memorable trip. All the better due to the lack of crowds on the way even though it was a Saturday in August. This seems to be a relatively undiscovered corner.