This space is located in the Depression of the Empordà, a wide flat area located in the northeast of Catalonia. It is bordered on the north by the steep terrain of the eastern end of the Pyrenees, which sinks into Cap de Creus, and on the south by the terrain of the Prelitoral range. This depression corresponds to tectonic basins that originated, during the Neogen period, by normal faults that sink rocky blocks and at the same time they are filled with continental or marine sediments.

To the north, not far from La Rubina, ancient Paleozoic rocks appear, usually granitic rocks among Quaternary outcrops. The sediments in this area correspond to the river and deltaic deposits of the Muga river. In this type of environment, it is common to find marsh sediments, with silt, sand and organic matter, as in the case of La Rubina, separated from the coast by coastal cords and dunes.