The Lonja is a civil building that is located in the Plaza del Pilar and faces the Basilica of El Pilar. It was built between 1541 and 1551 to centralize agricultural trade. The architect was Juan de Sariñena and the person who ordered it built was Hernando de Aragon. The building is the best Renaissance building in Aragon and has a rectangular plan. It was constructed with brick. There are three stories and on the ground floor there are three large entrances topped with semicircular arches. The arches of the higher floors are smaller. The upper floor has medallions with busts. Inside the building one can find columns that support a Gothic star-ribbed vault. Today the building is used for exhibitions.
The building is open from Tuesday to Saturday from 10 to 14H, and 17 to 21H. On Sunday the hours are 10 to14H. It is closed on Monday.