salt mines south of Geneseo.
Salt, whether rock salt for winter roads, or table salt, is something we take for granted, and yet it is such an essential in our lives. What if you wanted to know more about it, take a break from your regular studies? Hah hah, yes, you could use Wikipedia - but you should always take Wikipedia entries with a grain of salt, if you'll pardon the play on words ;-) Encyclopaedia Britannica has a good entry on salt for a starter.
We have some intriguing and recent, books here about salt, including Salt: A Grain of Life, or Salt: A World History. Good old Academic Search Complete would be a starting point to look for articles. The USGS (U.S. Geological Survey) has a page on salt and salt production, and the salt industry has an informative web page.