The Historic New Orleans Collection/Williams Gallery (New Orleans)

533 Royal St., Tuesday through Saturday (excluding holidays) from 9:30 a.m-4:30 p.m., and Sunday from 10:30 a.m.-4:30 p.m. For more info: (504) 523-4662 or www.hnoc.org.

“Surrounded By Water: New Orleans, The Mississippi River & Lake Pontchartrain,” through Sept. 20. Explores the natural history of the Mississippi and lake and the history played out along their banks and shores over the course of the last three centuries.