Johnson County is a center of activity for southernmost Illinois:
- Johnson County is the primary gateway to the Shawnee National Forest and home to the Hidden Springs Ranger District headquarters. The forest is a destination spot for outdoor activities, including hiking, fishing, hunting, biking, rock climbing, camping, and more.
- Vienna is home to the Tunnel Hill State Trail, a scenic biking trail that stretches from the primeval cypress swamps near Karnak, through the rocky hills north of Vienna, to the gentle farmland near Harrisburg.
- Goreville is home to the Ferne Clyffe State Park, featuring hiking, fishing, and interesting geological features.
- Johnson County is served by both Interstate 57 and Interstate 24.
- Two state penitentiaries are located in Johnson County (Vienna and Shawnee), providing a strong base of employment