The presentation of large hierarchies is still an open research question. Especially, the time-consuming calculation of the visualization and the cluttered display lead to serious usability issues on the viewer side. Existing solutions mainly address appropriate visual representation and usually neglect considering system resources. We propose a holistic approach for the presentation of large hierarchies using treemaps and progressive refinement. The key feature of the approach is the mature use of multiple incremental previews of the data. These previews are well-designed and lead to reduced visual clutter and a causal flow in terms of a tour-through-the-hierarchy. The inherent scalability of the data thereby allows for a reduction in the consumed resources and short response times. These characteristics are substantiated by the results we achieved from a first implementation. Due to its many beneficial properties, we conclude that there is much potential for the use of progressive refinement in visualization.