The first signs of salt production on the northern coast of Portugal are usually attributed to the Iron Age. However, there is evidence that this activity took place in the region at least between the late 3rd millennium, early 2nd millennium BCE. Data from two archaeological sites are presented and the so-called removable sinks and the sinks excavated in the rock are re-evaluated. Their execution techniques are also discussed. The data set was articulated with the natural and topographic conditions of the coast and the known climatic conditions for the time. They were also articulated with the occupation strategies during the Bronze Age.