Graphics3D[{Cuboid[{2, 4, 6}, {3, 5, 7}],
  Cuboid[{4, 6, 2}, {5, 7, 3}], Cuboid[{6, 2, 4}, {7, 3, 5}]},
   BoxRatios -> {1, 1, 1}, PlotRange -> {{-7, 7}, {-7, 7}, {-7, 7}}]
