The best outdoor activities for kids?

I absolutely love being outside in the spring in Nashville! Percy Warner Park and Radnor Lake Natural Area and Wildlife Refuge are two of my favorite spots. Both offer a variety of trails at various difficulties from a casual walk around Radnor Lake to a more intense hike through the hills at either place.

Centennial Park is home to the The Parthenon, along with a couple play grounds and some expansive green space as well. Depending on how old the kids are, The Parthenon can be a great cultural stop.

I lived in Nashville for several years and one of my favorite places close to the city was Percy Warner Park. 

http://rootsrated.com/nashville-tn/trail-running/mossy-ridge-trail-at-percy-warner-park  

Another place to check out is Cheekwood-Art & Gardens, typically has some great sites to see for people of all ages. 

http://www.cheekwood.org  

For the history buffs, there's a lot to see out towards Franklin (Tennessee) which is worth a visit in its own right.