Topology plays a central role in the modelling and management of n-d geo-information. However, hitherto the standardization of n-d topological data models is still at its beginning. A general model based on oriented hierarchical d-Generalised Maps is proposed to handle topology in object-oriented geo-database management systems. The implementation of the approach is demonstrated as module in DB4GeO, our service-oriented 3-d geo-database architecture. A 3-d tracks planning application example in the city of Munich is presented demonstrating the usage of the n-d topological model. Finally, an outlook on our ongoing 3-d geoinfo research in the Dubai region is given.