The Loomis Observatory sits on the campus of Western Reserve Academy and dates to 1838-1839, making it one of the oldest astronomical observatories in the country. The small brick building is modest in appearance but significant as an early American scientific installation — it housed instruments used for serious astronomical research in the mid-19th century, when Ohio was still on the frontier of the republic.
The observatory is not always open to the public, but the exterior can be viewed freely and the campus setting adds context. If you are visiting during an open period, the historic dome and telescope mechanism are worth seeing as examples of early American scientific infrastructure.