This was in the center of the fort, it was the powder keg/artillery.
Daniel Boone's fort is recreated in full, along with re-enactors, in the Fort Boonesborough State Park in Richmond, KY. It's about an hour's drive, give or take a little depending on what side of Cincinnati you are starting from.
It's $5/person (age 6 and up), and is well worth it. The re-enactors we saw were demonstrating how to cook on an open fire. Apparently there will be many many re-enactors after April 1 when the fort officially opens for the season. From the way the place is set up, it looks like there will be a Blacksmith, a basket weaver, someone carding wool and spinning it into thread (is there a name for that person?), a carpet weaver on a full loom, and much more.
For my husband and myself, the highlight of the place was in the authentic settler gift shop. They had hand-made period pieces such as wooden bowls and glasses, silverware made out of antlers, clothing from the period, flint stones with the iron for making a fire, and whatever that thing is called that they used to melt lead in and then pour it into molds for making bullets!