Most massive cluster found in the miniJPAS footprint, centred at RA = 213.6254, Dec = 51.9379. This cluster is also part of the redMaPPer catalog where it is listed as a cluster with richness λ = 33. The brightest galaxy has a spectroscopic redshift (from SDSS) of 0.289. Numbers in white next to galaxies indicate the photometric redshift derived from miniJPAS for galaxies with photometric redshifts between ∼0.26 and 0.31. More galaxies in this redshift interval (including some luminous ellipticals) are found at larger distances. The arrows indicate the direction and approximate distance of luminous galaxies found nearby and in this redshift interval. In red are drawn the strong lensing critical curves, estimated for fiducial sources at redshift z_s = 2 with the EasyCritics code applied to our data. We also show the X-ray iso-contour emission in the 0.5–2 keV range obtained by the analysis of XMM-Newton observations (cyan) in steps of 0.5 dex in surface brightness. 1 arcmin corresponds to ≈200 kpc at the cluster’s redshift.