Piazza Ghiaia, Market square in central Parma, Italy.

Piazza Ghiaia is a market square in the heart of Parma with multiple levels connected by a marble staircase. The layout combines covered arcade sections with open areas and displays architectural features from various building periods.

The square formed after the Parma torrent changed course following the 1177 flood, leaving a stony bed where the first fair of Sant'Ercolano was held in 1227. It served for centuries as a livestock market. In 1838 Duchess Maria Luigia moved the cattle trade away and had Nicola Bettoli build the Beccherie, a low neoclassical building with a portico of 50 Doric columns, 21 butcher stalls and an ice house, later donated to the city.

The square remains an active gathering place where residents go about their daily shopping and acquire regional goods. The covered sections and open areas define the character of a traditional Italian market culture that has endured through generations.

The market runs twice weekly under the glass "vela" roof, with the food stalls now replaced by a supermarket on the first underground level; levels -2 and -3 hold private garages. A granite and Verona white-stone staircase links the Ponte di Mezzo directly to the square, easing access from the river side.

Under Palazzo Medioli, an air-raid shelter was built in 1942, 8 m below viale Mariotti: over 400 m² in seven interconnected rooms, with a side corridor ending directly in Piazza Ghiaia. Seven ventilation outlets, one per room, remain visible along the right bank of the Parma torrent.