Another spot in Ohio that I have seen the signs for many times and never stopped is the Bowling Green State University Firelands campus in Huron. Last summer, upon learning there is an arboretum on the grounds, I decided to stop and went with another BGSU-grad and friend, Caitlin.
The James H. McBride Arboretum was lovely in the summer afternoon. There were plenty of flowers in bloom attracting all sorts of bugs.
The campus is located at 1 University Drive, Huron.