Barcelona's Llotja, or trade center, like those of the other main commercial centers of the Corona de Aragón (Crown of Aragon, the Catalano-Aragonese confederation that dominated Mediterranean trade between the 14th and 17th century), was designed to be the city's finest example of civic architecture. Perpignan, Castelló d'Empúries, Tortosa, Valencia, Palma de Mallorca, and Zaragoza all have splendid llotjas dating from the 14th and 15th centuries. Originally little more than a roof to protect merchants and their wares from the elements, Barcelona's present llotja was constructed in the sweeping, wide-arched Catalan Gothic style between 1380 and 1392. At the end of the 18th century the facades were (tragically) covered in the neoclassical uniformity of the time, but the interior, the great Saló Gòtic (Gothic Hall), remained unaltered and was a grand venue for balls and celebrations throughout the 19th century. The Gothic Hall was used as the Barcelona stock exchange until 1975, and until late 2001 as the grain exchange. The hall has now been brilliantly restored, and though public visits have not been formally established, any chance to see the inside of this historic hall will reveal Gothic arches and columns and a marble floor made of light Carrara and dark Genovese marble, with little windows showing the original Montjuïc sandstone paving stones under the marble. The painted, coffered ceilings, the neoclassical patio, and the grand stairways are among La Llotja's prime treasures. To slip into the hall, enter the Fine Arts Museum, wander over to the Saló Gòtic by walking down the stairs to the second, or main, floor and then descend the marble staircase and turn right.

The Escola de Belles Arts (Fine Arts School) occupied the southwestern corner of the Llotja from 1849 until 1960. Many illustrious Barcelona artists studied here, including Gaudí, Miró, and Picasso, whose father was an art professor at the school. The Picasso family reportedly lived nearby under the 15th-century beams and porches at Consolat de Mar 35 (corner of Carrer Trompetes), where a half-width wooden door opens into four floors of ancient apartments with exposed ceiling beams. The Reial Acadèmia Catalana de Belles Arts de Sant Jordi (Royal Catalan Academy of Fine Arts of St. George) still has its seat in the Llotja, and its museum is one of Barcelona's semisecret collections of art. Nineteenth-century sculptor Damiá Campeny's voluptuous marble sculpture of a moribund Lucretia, on the main floor upstairs to the right, and the young Marià Fortuny's drawings of heroic masculine nudes are the collection's stars.