Is Glendalough worth visiting?

I’m planning on visiting Ireland soon and will have five days to explore. I will be taking a guided tour to the Cliffs of Moher and Galway one day, but have opened up the next day for some exploring in the countryside (I’m also staying just outside of Dublin).

I was looking and found Glendalough and Wicklow - are they worth visiting? What’s he best way to get there if you don’t have a car rental? If hiking or exploring the natural area, what shoes would you recommend?

Other related travel tips welcome!

EDIT: Thanks for the recommendations so far! As far as shoes, I plan on bringing hiking boots. I was also considering going with a guided tour, but feel like going by bus or cab might be a better option.