Clusters of galaxies are ideal to study the effect of environment on galaxy evolution. We studied the clusters Abell 983 and 1731, targeted with a multiwavelength campaign of observations that include deep infrared Spitzer and near-IR Palomar imaging, and optical WIYN spectroscopy. The observations cover the vast range of possible environments, from the very dense cluster centre to the very rarefied cluster outskirts and accretion regions. The analysis of the specific star formation rate reveals evidences of galaxy pre-processing on a filament-like structure, extending from Abell 1731. Additionally, we found a decrease in number of star forming galaxies and AGN towards the cores of both clusters. A further comparison with the data from the Illustris simulation appears to confirm that dense environments are accelerating the ageing process of galaxies and blocking further accretion of cold gas that fuels both star formation and black hole accretion activity.