A wee bit of change

I need to back up to our first day in ireland for this story. We stopped in Cashel on our way to Cork on the first day in Ireland. The Rock of Cashel is where St. Patrick first used the shamrock to explain the Holy Trinity. The site is on top of a steep hill with signs clearly pointing to the appropriate parking lot, seemingly dispensing with the need for any parking attendants. We pulled into the one way lane and were immediately trapped in holy gridlock! And no available parking spots. We all agreed that we should exit, drive back to town and walk to the site. It took some time and patience, but we finally arrived at the exit gate. It was also unattended, but the bar would rise once you inserted 3 euro coins in the box. No problem except we had just arrived in Ireland and just had 20 euro paper bills. Ok. We decide to retreat and wait for a spot to open. As luck would have it, a big tour bus had unwittingly pulled up behind us. Some friendly discussion ensued and with a little shuffling, we were back in gridlock waiting for a spot. Indeed, we got a parking spot and walked slightly fatigued to the site entrance. I handed over my 20 euro note for our admission fee. The young Irish girl smiled sweetly and as she handed me some coins in return, said,"Mind you, you will need just a wee bit of change to exit our parking lot!"