Efficiently modeling geospatial databases has always posed a challenge for systems analysts, developers and users. Based on 17 years of research and experimentations as well as feedbacks from users in many countries, an approach is proposed to facilitate conceptual modeling of geospatial databases. In particular, the proposed approach combines an Agile philosophy with Plug-ins for Visual Languages (PVL) to offer a unified language describing any 2D and 3D geometry as well as spatio- temporal objects. Although usable with any modeling language in any CASE tool, this solution is at the center of the UML-based Perceptory CASE tool which adds a rich repository offering a sound basis to build spatio- temporal ontologies. We conclude with an overview of a new project called ISTory (Integrated Spatio-Temporal repository) which aims at supporting transactional database modeling, analytical database modeling, spatio- temporal ontology building and other activities.