The Red Barn event space on the Hampshire College campus in Amherst, MA. We had the date reserved but some family stuff made it impractical.
I've always loved this space -- holds about 160, beautiful views of nearby mountains, the date will be at the absolute peak of fall foliage. We were sorry to give up the date... hopefully someone can put it to use!
Happy to answer whatever questions I can, but feel free to contact them directly if you're interested. The staff there were wonderful to work with, provided us with lots of recommendations for local vendors. The space works for a wedding ceremony, as well as the reception.
Thanks! 
Tim
***

