For Day 4 of this trip, I recommend exploring Galway in the morning. It is no fun to drive East in Ireland in the early morning, with the bright Northern European sun in your eyes all the way. So walk around Eyre Square, down to the quays and the Spanish Arch, and if it's a sunny day, out to Salthill.
After early lunch, head East for Dublin. In recent years, this road has been upgraded in places, so you should make good time.
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I recommend stopping off in Kilbeggan, which you'll reach after Athlone (after you cross the Shannon). Kilbeggan is home to the oldest continuously licensed whiskey distillery in the world, although disappointingly it no longer actually brews whiskey. The distillery is driven by a water wheel in a small river, very picturesque. There are also coffee shops locally for a snack or lunch.
More Irish Road Trip recommendations:
Oman’s Top 5 things to do in May 2017
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