The Lonja de la Seda de Valencia or Lonja de los Mercaderes is a Valencian civil Gothic masterpiece located in the historic center of the city of Valencia.

Declared, in 1996, a World Heritage Site by Unesco, it is located in the Plaza del Mercado, number 31, in front of the Church of the Santos Juanes and the Central Market of Valencia.

Francesc Baldomar was the author of the original project of the Lonja de Valencia, he began to develop it between the years 1470-1471.

His disciples Joan Ivarra and Pere Compte received in 1481, five years after his death (1476), the commission to finish building it according to the magnificent original plans that he had drawn in his last years of life.

His approach followed the model of the Lonja de Palma de Mallorca, becoming an emblematic building of the wealth of the Valencian Golden Age (15th century) and a sample of the commercial revolution during the Late Middle Ages, of the social development and of the prestige achieved by the Valencian bourgeoisie.

The construction of the Lonja has been interpreted as the result of the commercial prosperity achieved by Valencia in the 15th century, and as a symbol of the power of the city to attract merchants, at a time when difficult times were already looming for the local economy derived from the discovery of America and the consequent displacement of trade from the Mediterranean to the Atlantic.

The auction houses in the Crown of Aragon were built following the same scheme: a room with a rectangular floor plan supported by columns. The one in Valencia was preceded by the Lonja de Barcelona (1380-1392) and the Lonja de Palma (1420-1448), with helical pillars where the ribbed vaults of three naves are supported.