A salt kettle in Marion, VA.
The plaque reads:
Once used industrially in nearby Saltville, brine from wells was evaporated to solid salt in these kettles over wood fires. From 1790 to 1895, such salt was shipped throughout the southeast and was the cause of important battles during the War Between the States.
Kettle donated to Smyth County, Virginia by Dr. D.C. Boatwright and the heirs of Charles J. Duncan.
Plaque donated by Olin Mathieson Chemical Corporation, Saltville, Virginia.
1959
Preservation in Pink 
Wow I learn so much from you! I would have said it was a sugar kettle. Thanks for teaching me something new!
Thank you! And I’m glad to share what I learn. I would have guessed sugar as well, like I’d seen in sugar mills.