Amongst the many hundreds of coordination cages to appear in the past 30 years, the Pd2L4 topology, first described by Steel, is the simplest, arguably the most versatile and one of the most well-studied. It has been investigated in multiple contexts, as it's host-guest chemistry can be tuned to bind anions, as well as neutral species. This versatility has allowed it to be exploited for a number of applications that involve the binding of drug and imaging molecules, 11 as well as substrates for catalysis. Paramagnetic M2L4 lantern cages are much less well explored, 14 indeed investigations of the magnetic behaviour of any supramolecular cages remains virtually unexplored. However, the host-guest chemistry of these systems offers a range of potential advantages for the exploitation of magnetic materials properties. These include, for example, the reversible inducement of magnetic exchange interactions, the encapsulation of unstable/reactive molecules or those with unusual geometries/coordination numbers, solid-state dilution, and the tuning of magnetic anisotropy. Such properties are sought-after for the construction of single-ion and single-molecule magnets, electron-spin based qubits, and may find application in magnetic sensing, switching and molecular recognition. Functionalisation of the organic framework would also aid surface deposition and the transformation of 0D molecular cages to 2D sheets and/or 3D MOFs imbued with the same physical properties. Successful ingress of a magnetic guest into a magnetic host may have little effect on magnetic properties if there are no significant interactions between the two, nor any geometrical change in either component. However, this is unlikely if size/symmetry/electrostatic matching is efficient. Encapsulation may solely induce structural changes to the host/guest and this has previously been shown to have significant impact upon, for example, the magnetic anisotropy of 3d transition metal ions in magnetic MOFs, and the high spin -low spin transition temperature in spin crossover materials. Indeed, recent studies of single-ion magnets have shown how crucial geometry is in determining magnetisation relaxation dynamics, and thus metallosupramolecular cages could play a key role here if their internal cavity can be designed to suit a specific d/f metal ion geometry. Covalent bonding through an intervening organic/inorganic ligand or a short dipolar interaction between the metal ions in the host and guest will mediate a magnetic exchange interaction, the sign and strength of which can be controlled by the nature of the linker and the identity of the metal ions. This then allows for control over the magnetic ground/excited states of the cage, the manipulation of which underpins application in a breadth of technologies. Interesting potential guest molecules include the rhenium (IV) hexahalides, [ReX6] 2-, that possess very large spin-orbit coupling constants (λ ~ 1000 cm -1 in the free ion) that results in significant magnetic anisotropy. In addition, spin delocalisation of the electron density from the metal to the halide imparts significant Re-X•••X-Re intermolecular exchange interactions which can be strong enough to induce magnetic order in the salts of these anions at relatively high temperatures. For example, K2[ReBr6] shows antiferromagnetic order below 14 K.