There's not a whole lot to see in Zeandale. The homes are neat and well-maintained, and there's a small community center with a park nearby. Apparently, there is (or at least used to be) a group of community artists called the Zeandale Arts Project here.
We enjoyed stopping for a while -- the boys especially approved of the tall twin slides that allowed them both to go down at the same time.
The town was originally founded in the 1850s, so enthusiasts of Kansas's pioneer days might find a visit worthwhile. Nearby Pillsbury Crossing (over historic Deep Creek) is a beautiful spot, so my family visited it often when I was growing up.
A very informative master's thesis by Marilyn Louise Geiger on Zeandale Township is available at Archive.org. Another, much shorter, history paper by Leota Boisclair on the same topic is available at Lost Kansas Communities. The Riley County Historical Museum also has an interesting page on Josiah Pillsbury, the namesake of Pillsbury Crossing and the man who named Zeandale.