The Hemp Exchange of Castellón de la Plana is a Baroque building with a rectangular floor plan, constructed in the first half of the 17th century under the direction of the master builder Francisco Galiança. It was erected as a market for the hemp trade, a raw material of great economic importance in the region at that time, on the site of an earlier structure that was demolished for this purpose.

In its original layout it was a single-storey building with two façades open to the exterior, each with two large arches supported by columns of the Tuscan order. The only original sculptural element was the coat of arms of the city, which presided over the façade. This formal sobriety is characteristic of Valencian civil Baroque architecture of the period.

Over time an upper floor was added, whose façade was decorated with allegorical paintings by the Neoclassical painter Joaquín Oliet. The intervention substantially altered the appearance of the building: a layer of pictorial ornamentation of a learned character was superimposed on the austere base of the original.

The building is listed as a Bien de Interés Cultural (Asset of Cultural Interest) and is inscribed in the Patrimonio Nacional and in the Patrimonio Cultural of the Generalitat Valenciana. Following its restoration it became part of the network of spaces of the Universitat Jaume I and was converted into a cultural centre, hosting exhibitions, lectures and courses.

It is located on Calle Caballeros, in the heart of the historic centre of Castellón de la Plana, very close to the Plaza Major and other monuments such as the Fadrí and the Church of Santa María la Mayor.