From the World Heritage inscription:
Built between 1482 and 1533, this group of buildings was originally used for trading in silk (hence its name, the Silk Exchange) and it has always been a centre for commerce. It is a masterpiece of late Gothic architecture. The grandiose Sala de Contratación (Contract or Trading Hall), in particular, illustrates the power and wealth of a major Mediterranean mercantile city in the 15th and 16th centuries.
The shocking thing about La Lonja isn’t that it is a World Heritage Site, it is that the other things around it in central Valencia are not. The Lonja itself is a very simple building today with an empty interior. It is one of many buildings in the old city of Valencia which is part of its rich merchant history. Pay close attention to the gargoyles on the exterior of the building and some of the internal stone carvings around the doors. You will find some shocking surprises.
View my complete list of World Heritage Sites I’ve visited.