On your way back to Arkansas, you might want to meander a few hours off of your path to go to a place called the Ave Maria Grotto. It’s just a few hours south of Nashville, in Cullman, Alabama. My forebears are from that town and when I was a kid, whenver our travels took us near that town we’d stop in for a tour around the Grotto.

Your mention of the gift shop with found items reminded me of this place and I think you’d totally dig it. The Grotto is on the site of a Benedictine Monastery. One of the priests there had a lifetime project wherein he’d make small reproductions of the Holy Land and famous buildings from around the world. It was during the 1930s – 1950s mainly, and not much money to be had, so he used concrete and found materials like shells, glass bottles, old tiles, etc. They’re all made on this big hillside with a walking path. It’s truly a sight to behold.

Here’s a website: http://www.avemariagrotto.com/ though the one pic (???) they have posted really doesn’t do it justice. Check it out here as well: http://www.roadsideamerica.com/story/2015

If you’ve got the extra time on the way back, I’d highly recommend it.