Update (Wednesday, 9:17 a.m.): The answer is a fermentation vat at the Maker's Mark distillery in Loretto, Kentucky.
Think you have a good eye for identifying mysterious photographs? If so, you could win a prize in the CNET Road Trip Picture of the day challenge.
Later this month, I'll be starting Road Trip 2010, my fifth-annual journey around a region of the United States in search of the most interesting places one can visit. In past years, I've traveled a total of more than 18,000 miles in the Pacific Northwest, the Southwest, the Southeast, … Read more