Have you looked into the Florian Gardens? We are having ours there, and it's absolutely beautiful! They have also been extremely helpful so far & the cost for renting a garden is quite reasonable! The only thing is that you either have to get your own back-up location incase of bad weather, or rent one of their rooms for a back-up. You can check out their website at www.thefloriangardens.com. Hope this helps. Good luck!
Phoenix Park downtown is a spot to consider...Take a look at the parks and find one you like. I was at wedding at owen park and it was really nice.
Irvine Park or Kamp Kenwood are pretty cool.
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