An open-air astronomy park on Route 664, a couple of minutes west of the Old Man's Cave area, named in honor of Ohio astronaut and senator John Glenn — a tribute from his home state, since the park opened in 2018, after his passing in 2016. By day it's a paved, level, barrier-free plaza built as a working sun-calendar aligned to the solstice and equinox, with the solar system modeled to scale so visitors can walk the planets on foot. A roll-off-roof observatory houses the park's largest telescope. The real draw, though, is after dark: Hocking Hills holds some of the darkest skies in Ohio, and the park hosts free public stargazing on clear Friday and Saturday nights, spring through fall, weather permitting. The grounds stay open and free around the clock.
Just ahead on your right, tucked in its own clearing just off Route six sixty-four, you'll spot a place most folks drive right past in daylight — and on a clear night, it's one of the best reasons to come back. This is the John Glenn Astronomy Park. The name honors John Glenn, Ohio's own — the first American to orbit the Earth in nineteen sixty-two, and four terms a U.S. senator after. Straight talk on that, since it matters: he died in twenty sixteen, and the park didn't open until twenty eighteen, so he never set foot here. It's his home state naming its darkest skies for him, the way you'd name a thing for somebody you're proud of. In daylight, what's here is modest and easy — a paved, level plaza you can stroll or roll right across. But look closer and it's clever: the whole ground is built as a sun-calendar, squared up to the solstice and the equinox, and the solar system's been laid out to scale so you can walk the planets one by one, from the sun on out. The telescopes you can see parked under that roll-off roof, though — they're a nighttime business. So here's the pitch: this is a daytime peek at a nighttime place. On clear Friday and Saturday nights, spring through fall, they open it all up and run free public stargazing — real scopes, folks who know the sky, no charge. If your evening's open, drive back after dark. It's worth the trip.