This is probably the best trail in all of the Atlanta area. It entails over 16 miles of trails. This is also one of the most popular trails around, but because of its size you never feel crowded (except at the parking lots). Check out the renovated and expanded Visitor Center, it is loaded with Civil War info.
Directions: Located west of Downtown Marietta, this park is so large that there are several ways to get to it. Also, there are many places to park your car other than at the Visitor Center. To get there from Downtown Atlanta take I-75 north then turn left at Barrett Parkway. Turn left onto Old Hwy 41. Follow Old 41 until you come to a traffic light (Stilesboro Road), turn right and then an immediate left into the main entrance.
Two trails begin just to the right of the Visitor Center (as you face the Visitor Center from the parking lot). One trail takes you up to the top of the mountain, then on to Little Kennesaw mountain and connects with the remaining trail system. The other trail takes you half-way around the mountain and on to the other end of the park. See the trail map for more details.
Parking: Main Entrance (Visitor Center); also along Burnt Hickory Road; also along Dallas Road ; also John Ward Road; and along Cheatham Road.
Conditions: Well maintained dirt path with good footing for the most part. Very scenic and historic. The path frequently accommodates two or more abreast. Drinking fountain and restrooms at the Visitor Center.
For further Info.: http://www.nps.gov/kemo/index.htm
Look at the trail map: http://www.nps.gov/kemo/kemomap.gif
Another trail map (.pdf file): http://www.nps.gov/chat/pphtml/maps.html
Photos of this beautiful park