With miles of trails (some even handicap accessible), interpretive signage, beautiful landscapes, an impressive bridge spanning Flint Creek and nature center staff close by, Starr's Cave is certainly the top choice for trail hikers of all ages.
Another park close to Burlington with miles of trails and picturesque forests, Hunt Woods is a popular destination for families wanting a close-to-home place to connect with nature.
Closer to Mediapolis, Luckenbill Woods also offers fantastic forests, prairies and even a couple ponds (with decent fishing, by the way) along with its network of trails.
There are many more places to check out in Des Moines County. Check out all of Des Moines County Conservation's Recreation Areas.