Ah well, then! Counties Clare and Galway are considered Midwest. I assumed you were heading south from Shannon. In that case you should definitely add the Burren to your itinerary. It's a karst landscape and rather unique. https://burrenbeo.com/ If you decide to come (t)here I could show you around for a bit, schedule permitting, or at least give you some detailed pointers.
Plenty of places in Connemara too. The coastline, Roundstone Twelve Bens, Letterfrack with the tiny but interesting national park (more of a nature reserve), the beautiful Renvyle peninsula, Leenaun (where "The Field" was filmed) , the stark famine road from Delphi to Louisburgh, the backroad from Leenaun via Maum to Maam Cross, Inishbofin island.