The Cahaba River, Alabama's longest free-flowing river, runs along Birmingham's western edge and is one of the most biodiverse rivers in North America. The stretch near the Cahaba River National Wildlife Refuge and the town of Cahaba (the first state capital, now a ghost town) is accessible for canoeing, kayaking, and hiking.
The river is particularly notable for its aquatic biodiversity — it contains more species of fish per mile than any river east of the Mississippi and is home to the endangered Cahaba shiner and the cahaba lily, a shoal lily that blooms in May and June. The Cahaba Lily Festival in May draws visitors to see the blooms in the river shoals near West Blocton, about 40 miles southwest of Birmingham. For a closer look, the Hargrove Lake area near Bessemer offers canoeing access.