Shorter trip ideas from Boston?

Planning on a short trip with my girlfriend in the first week of June (6/3-6/7), I do have work on 6/3 but should be off by 5 pm so it’s more of a travel day as will be 6/7.

Was thinking between Montreal or Acadia National park or if someone has a better idea I’m open to it. We both like nature and cities and we both haven’t been to either of these places so it’s really a toss up. Budget shouldn’t be an issue.

Thanks!