1. Take a storm chasing tour! Believe it or not, when in the middle of the country; this is a thing. Straight down the middle of the flattest states in the country is what is known as Tornado Alley. It runs from southern South Dakota down through the Texas Panhandle. Years ago there was a movie called "Twister". You may have heard of it. What happened was ridiculous. It spawned and entire adventure travel subset.
There are a lot of companies, mostly operating out of Oklahoma and Texas, although I have seen some in Kansas, who will take you out to chase storms; aka, tornadoes. This isn't for the feint of heart. These tours can be a day or several; depending on what you want to get out of it. What you will get is an adrenaline rush. For someone who's been around a tornado or two, and not by choice, I'd say prepare yourself for this one.
That being said; if you can't get enough adventure and happen to be in Tornado Alley; this is probably something for you!
https://extremetornadotours.com/
https://www.tornadicexpeditions.com/
2. The Cerro Gordo Mine and Ghost Town, near Death Valley, California. Nathan Barry decided to buy a ghost town in 2018 with a friend and has been turning it into a destination ever since. The desert lands of California were abuzz with activity during the gold rush years of the 1800's. But after the boom was over, so was the town. In its new incarnation, the old ghost town is a location to visit. You can come and visit, see the old mines, see the old town, buy some souvenirs, and even stay the night if you like. There aren't many creature comforts here, but it will be a massive adventure. Barry is a generous host and knowledgeable about the history of the property, so come, learn, and experience this historic mining town.
https://nathanbarry.com/cerro-gordo/
https://whichmuseum.com/museum/cerro-gordo-mines-keeler-20263/opening-hours
https://store.cerrogordomines.com/
https://www.youtube.com/watch?v=QS0kyvIXOu4
3. Falkenstein Castle, Burnet, Texas. This one's fun. They say it's not too far from Austin, and it's a real castle. The creators, the Young's visited Neuschwanstein Castle in Bavaria and decided to make one of their own. It took 10 years and was a labor of love. Now, the castle is available for events like weddings and so forth. For the right price, you can bring up to 12 people and stay for a couple of nights with the entire castle to yourself. It's a once in a lifetime experience, and something to keep in mind if you happen to be in central Texas!
https://www.hillcountrycastle.com/
https://www.airbnb.com/rooms/45767504?source_impression_id=p3_1714593727_ne0i3W5QQ61S0quw
https://www.youtube.com/watch?v=KL20nEif51Y
https://texashillcountry.com/falkenstein-castle-fairy-tale/
https://www.facebook.com/falkensteincastleburnettx/
4. Ragbrai, aka, Register's Annual Great Bicycle Ride Across Iowa, Iowa. I've been to Iowa. It's one of those places where you kind of end up making your own fun. Not a lot of tourist attractions. The biggest event for decades was the state fair. Corn is king in the state, and if you don't believe me, you can come and see it for yourself. In 1973, Ragbrai was created. It's a 450 or so mile bike ride across the state. It happens every year. It's become the biggest non competition bike ride in the world and the longest running as well. There are events, food, entertainment and a lot of fun along the way. Currently, they've become so popular that you can't just join like you used to be able to. May 15th is the last day for registration for this year's 8 day biking adventure.
https://www.facebook.com/RAGBRAI/
https://www.iowacorn.org/education/ragbrai-iowa-corn