A Second City together with Healing of Land are part of a greater body of mixed-media works that Nassimbeni is working on dealing with the theme of subterranean Johannesburg, and how life below ground can support life above ground, both in nature and industry (e.g. mining). Nassimbeni explores the hidden city beneath, including man-made structures such as water and drainage systems, mine shafts and tunnels, as well as the underground root systems of plants and trees, underground caves and other naturally occurring underground structures.
Both Healing of Land and A Second City are based on City Deep Mine. Healing of Land shows the plan of the mine’s decommissioned shafts and tunnels, while also playing with the allusion of a mirror image and symmetry of the above and under ground world. A Second City depicts topographical map lines of the mine. In both works the introduction of the colour blue symbolises acid mine water, which Nassimbeni asserts should not be seen as something negative, but something that can be overcome, and that originally is something pure.