Via Examiner.com, a quick recap of Kennesaw Mountain, beside Lake Allatoona:

The museum at Kennesaw Mountain National Battlefield Park in Kennesaw carefully sets the stage for the events leading up to the Battle of Kennesaw Mountain and what happened afterward. A 20-minute film also helps visitors understand all that was at stake for both the Union and the Confederacy leading up to and during the battle, which lasted from June 19-27, 1864. The battle was part of Gen. William T. Sherman’s Atlanta Campaign and caused Confederate Gen. Joseph E. Johnston to withdraw from the area, moving his troops first into Smyrna and then to Atlanta.

After the battle at Kennesaw, Johnston was replaced as the commander of area soldiers by John Bell Hood. About a month later, Sherman was firing artillery into Atlanta and ordering the evacuation of civilians. The long and short of it is that Kennesaw Mountain was what stood between Sherman and Atlanta, and the battle that ensued there was critical to the Civil War. Over 5,300 soldiers were killed there.

Today the park is open during daylight hours. Besides the museum and film, the park also features a mountain-top view of the battlefield, picnic areas and over 17 miles of hiking trails. The grounds feature monuments, cannon emplacements and earthworks.