This paper describes the development of the CORSSA array (CORinth Soft Soil Array) in the framework of the European project CORSEIS, which takes place in the highly seismic region of Aegion, in the Gulf of Corinth, Greece. An array of surface and down-hole accelerometers and pore pressure transducers is deployed in the hanging wall of the Aegion Fault, an active normal tectonic feature that crosses Aegion city. The scope of this array is to study the physics of wave propagation, the non-linear soil behaviour, liquefaction phenomena and the effects of surface geology on strong ground motion. The surface geology is well constrained by a detailed geotechnical and geophysical survey including dynamic soil tests. Typical recordings and preliminary 1D SH ground response analyses are presented herein, illustrating the importance of the experimental array to study complex site effects including non-linear phenomena in the vicinity of faults and topographic relief. To cite this article: