During the Future Science with CMB x LSS conference underway at Kyoto University, Japan, the results of a detailed mapping of dark matter in a part of the universe were presented. Three articles available in preview and submitted to “The Astrophysical Journal” illustrate these results, obtained using observations conducted at the Atacama Cosmology Telescope (ACT) in Chile, which operated between 2007 and 2022. This map (Image courtesy ACT Collaboration) was obtained by analyzing the cosmic microwave background radiation and its deviations caused to the gravity of massive structures such as concentrations of dark matter.