Directions to Letterkenny from Dublin:

For those of you driving up from Dublin it's about a 3.5 - 4 hour drive to Letterkenny. Even with bad traffic it's never taken me more than 4 hours and I'm a safe driver.

Directions are as follows:
Take the M50 and M1 out past the airport.
You'll go through 2 toll booths.
Head towards Belfast.
About 10 miles after you cross over the "artistic" looking bridge there will be an exit on your left to Ardee.
Take the exit and head towards Ardee and keep on following the signs for Derry.
You will by-pass Omagh and when you get to Strabane follow the signs for Lifford.
When you pass through Lifford follow the signs to Letterkenny.

This is the fastest and easiest way to get there. Some people reckon going via sligo takes about 7 hours so I wouldn't recommend that!