MUSE white-light image (cube averaged over all wavelengths, logarithmic scale, arbitrary unit) over the full field of view of the observations of COSMOS-Gr30. Spectroscopic and photometric group members from the zCOSMOS 20k group catalogue (Knobel et al. 2012) are indicated using red squares and green diamonds, respectively. The 44 group members that are unambiguously identified in the MUSE data cube are marked with blue circles. The black square represents the area studied in more detail in this paper. The physical scale at the redshift of the structure is indicated at the bottom right.