We present a unique multiwavelength dataset of the Abell 901/902 supercluster at $z=0.16$. The environment of the structure is well characterized by weak lensing analysis, galaxy dynamics, and X-ray imaging, and we examine how galaxy properties correlate with these measures of environment. We examine the star-formation–density relation and find a surface mass density threshold above which star-formation in supercluster galaxies is truncated, and that this transformation affects primarily the faint end of the star-forming galaxy population (down to $M^*+6$). In addition, we present a preliminary dynamical analysis of the spectroscopic sample ($n∼ 300$ galaxies), revealing a bimodal distribution of galaxy velocities and significant substructure.