The wooden boardwalk overlooks the "Whispering Dell Sinkhole". A close up view of the Water Tower which was burned by vandals in 1976. You cannot go inside the Water Tower but I was able to stick my camera inside to take an interior photo. I believe the Water Tower once had living quarters below for servants.
Ha Ha Tonka is considered a wonderful example of "Karst" Topography. Karst topography is typified by caves, springs and sinkholes. Above is a picture of Whispering Dell Sinkhole which was formed by a partial cavern collapse. Signboard along boardwalk explaining the sinkhole. This Missouri State Park is well marked and very informative. Whispering Dell sinkhole is 150 feet deep.
Another angle of the Water Tower.
The Missouri Archives contains an interesting old photo of the Water Tower at: