PIQUA – Mainstreet Piqua’s annual Harvest Days fall celebration is set to return to the downtown on Saturday, Oct. 12, from noon to 6 p.m. Mainstreet Piqua will host the free, one-day event which brings together all things fall, along with local food favorites, live music and lots of activities. The fall event will offer pumpkin painting, craft vendors, kids’ activities, a retail open house, food trucks and more, said a Mainstreet Piqua press release.