Kennesaw Mtn is a cool place to go for both exercise & a history lesson. It's free unlike many other similar sites. It's got a lot to offer civil war buffs - there are many historic landmarks with signage to educate you & they've even gone digital - you can use your smartphone to scan some signs & go to audio/video for more info. There are various paths to take - if you want more of a flat, easy trail go to Cheathem Hill, more moderate to challenging go to Pigeon Hill &/or Kennesaw Mtn. I've seen all ages there & it's appropriate for couples, families, friends, solo. We also take our dogs there so it's pet friendly (but remember to bring doodoo bags) & go early to avoid overheating & take water of course.