It's used to add a sense of "how much" (or in this case, how little) the subject actually traveled. Even though they said they went on vacation, it was no more than going to the next town.
I'm going to adjust the English translation a bit to better reflect this, so thanks for the comment!
LOL. To be honest, I am seeing this expression for the first time as part of my N3 grammar studies. So I hope somebody with more experience and knowledge can comment on your correction. Otherwise, your grammar explanations really have been very helpful, much more than the ones in the study book I am using!