secret train ride....
Area K25 is a patch of Oak Ridge where the famed Manhattan Project was developed (nuclear bomb in World War II).
To get into this secret (now declassified) area, you board a train that is 7 miles away from the site. On the train ride, you will hear about the involvement of the United States in the nuclear race. Some of the scheduled rides offer diner (at additional cost). As you enter the compound, the guide will instruct you on which buildings and structures were employed to perform each of the steps necessary for completion of the nuclear weapon. There is a spiel about individuals who played key roles in the project and how the project was concluded and the use of the area since. The train exits the compound and rides back through the lovely countryside , to the original point of departure.
The whole trip costs $12 (2003) and takes about an hour and a half.
The train has restroom facilities and is completely air-conditioned (summers are warm in Tennessee)