The second time I visited Ha Ha Tonka I went on a trail I'd missed the first trip — the one that loops through the castle ruins, drops down to the spring, crosses the natural bridge, and climbs back through cedar glades. About five miles total. I did it in the kind of July heat that Missouri produces specifically to test your commitment, and it was worth every sweated-through shirt.
Ha Ha Tonka is Missouri's premier showcase of karst geology, and the park makes that claim earnestly because it's true. The natural bridge — 70 feet wide, spanning 60 feet, reaching 100 feet in the air — is a piece of rock formation that you walk under and immediately want to see again from every angle. The Colosseum sinkhole nearby is 500 feet long and 300 feet wide, a collapsed cavern that now grows ferns and wildflowers in its shaded basin.
The spring at the base of the bluff is Ha Ha Tonka Spring, Missouri's 12th largest, discharging more than 48 million gallons of water daily. The water runs cold and blue-green into the Lake of the Ozarks arm that cuts through the property. On a hot day, sitting near the spring while mist drifts over the water is about as good as it gets.
The castle ruins above remain the draw that most visitors come for, and they're worth it on their own merits. But the park around them is doing its own serious work. Budget a full day and go early enough to beat the heat by at least a little.