On the first weekend of each month (Saturday and Sunday), the Piazza Grande and surrounding streets fill with around 600 antique and vintage dealers for the Fiera Antiquaria — one of the oldest and most respected antique markets in Italy. The goods range from serious museum-quality pieces to affordable vintage furniture, ceramics, prints, and curiosities.
The Saturday is marginally less crowded than the Sunday; serious buyers arrive early on Saturday morning. The market overflows into several adjacent streets, including Via della Fonte and Via dei Pilati. Quality varies considerably — look carefully. There's no entrance fee, and the surrounding cafes open early to serve the dealers.