Metal particles deposited on thin oxide films have been shown to be suitable model systems for studying structure-reactivity relationships of metal catalysts. A detailed understanding of the surface structure of the oxide films is a crucial prerequisite. It has been previously shown that well-ordered FeO(111), Fe3O4(111) and alpha-Fe2O3(0001) films can be prepared on a Pt(111) substrate in a controllable manner. In this presentation, we report on the determination of the surface structure of these iron oxide films using scanning tunneling microscopy, temperature programmed desorption and vibrational spectroscopy of CO as a probe molecule. In particular, we have found that the Fe3O4(111) surface is terminated by 1/2 monolayer (ML) of iron, with an outermost 1/4 ML consisting of octahedral Fe2+ cations situated above a 1/4 ML of tetrahedral Fe3+ ions. The most strongly bound CO, which desorbs at 230 K, is assigned to adsorption to Fe3+ cations present at the step edges, whose geometry is predicted on the basis of coordinative unsaturation and excess surface charge concepts. For the alpha-Fe2O3(0001) surface, experimental and theoretical evidence is presented which shows that the hematite may be terminated with ferryl (Fe=O) groups, which has never been considered for iron oxide surfaces. In addition, the structure and adsorption properties of metals (Pd, Au) deposited on these films are studied. For example, CO is found to react with lattice oxygen of Fe3O4 at the Pd/oxide periphery. Oxygen adsorption at elevated temperatures resulted in structural changes of the system. The results for the model catalytic systems supported on the iron oxides are compared with data previously obtained for other (non-reducible) oxide films.