If you find yourself in Umbria during the month of October, find a way to Trevi for their Sedano Nero (black celery) festival. Different events occur on different weekends, but the sale of celery is marvelous. Sedano Nero is listed on Slow Food's Ark of Taste (one of those foods that is vanishing). The heads are gigantic, and the stalks boast few wires or strings, but really the appeal is the reverence for which celery is treated in Trevi. During the season, restaurant menus are filled with sedano nero (try the farro soup with celery, fabulous!), and the hub of people gleefully purchasing giant bags of celery during the festival is glorious. October is also the month of sausage making, so grab a free cup of new olive oil with a stalk of celery, while you wait for your sausages to be perfectly grilled. And imbibe the joy of people dedicated to the history and uniqueness of their food.