The most important geographical characteristic
on the Costa Daurada is the Prelittoral Depression located between
the two mountain ranges that border the Mediterranean system.
Crossing the region from north to south, it is the result of a tectonic trench formed by the folding of an old Hercynian mountain range.
Towards the end of this Tertiary orogenic paroxysm there were several collapses in the Prelittoral Mountain Range which gave rise to valleys and bowls of various sizes.
The Conca de Barberà and the Cubeta de Mora are good examples.
The rocks are basically calcareous in the
mountain areas with different kinds of Paleozoic outcrops.