Clarksville, Tennessee, in Montgomery County, is a bustling city built by the tobacco trade. The Customs House Museum & Cultural Center, in the city's historic district, was originally constructed as a US Post Office during the tobacco boom. Now it has been converted into art gallery, history center, and hands-on children's museum. Just outside of town is the Dunbar Cave State Park, where visitors can hike through caverns that were once mined for gun powder and used for big band concerts.