Magnetic systems generally involve magnetic moments on individual ions or atoms with coupling between them that can induce magnetic ordering. An alternative paradigm is realised when small groups of ions share a magnetic moment with coupling between the groups that may induce magnetic ordering. Recently spin liquids with spin-1/2 moments on molecular dimers and LiZn2Mo3O8 with spin-1/2 moments on Mo3 trimers have attracted enormous attention in frustrated magnetism. Here we propose to study La3Re2O10, which has spin-1/2 moments on Re2 clusters on a distorted triangular lattice that order via two transitions around 18K. The moment size appears to be enormously suppressed in the ordered state and there is evidence of short-range ordering well above the antiferromagnetic transitions, so this system should be ideal for study with ISIS muons.