Abstract: The invention concerns an outdoor bio-tower (10) for placing in a garden or on a patio, wherein the bio-tower (10) promotes biodiversity in outdoor environments. The bio-tower (10) comprises a framework defining a plurality of compartments each providing separate habitats suited to different species of flora, fauna, micro-organisms and/or fungi. The compartments include at least a first internal dry compartment with an access for creatures requiring a dry habitat, and at least one separate second internal wet compartment containing a tray (27) which may retain water and access for creatures requiring a wet habitat. The two internal compartments are surrounded at least in part by external compartments filled with a growing medium, such as soil, that serve for growing plants and that offer insulation to the internal compartments.