The amphoras full of fish or of the precios garum salse leave for the port.  Mazarrón has one of the most important industries of the final years of the Roman Empire. In this period, from the 4th to the 5th Century BC, the salting factory was immense, and possibly the region’s main source of income.

What is today the Roman Salting Factory Museum is only a part of one large factory which occupied an extensive area on the right side of the bay of Mazarrón. Inside there remains part of the structures used for making essential products in many of the recipes which are still preserved from the Roman imperial era, among them the saltings and the famous garum sauce, a delicacy fetching a high price on the market, today comparable to truffles, saffron or caviar.

There remain from the factory basins or tanks for the salting. In these, fish, especially tuna, was tenderized with salt to make garum. The tuna was caught in tunny nets, cleaned and cut into slices, which were stacked covered in salt and various aromatic herbs for 20 days. The fish leftovers were used for the garum, a sauce fermented in salt with such an intensive flavour that possibly today it would be inedible. It was used to increase flavour in meals, as today stock cubes are used, as has been reflected in a number of cookery books from the period.

Both the saltings and the garum were packed and hermitically sealed in amphoras for their transport throughout the empire.

This industry also attracted other auxiliary crafts, such as esparto grass and pottery. In the museum, as well as the exhibition of the remains and the period corresponding to the factory, there is information about the rich architectural heritage of Mazarrón and its port.