Terrain rendering is widely used in industry and research. GIS software packages as well as navigation systems make use of ter- rain rendering to visualize terrain information. Recent trends in research show that scientific terrain visualization is shifting more and more to an interactive analysis tool. This allows domain spe- cific users to perform visual analysis tasks within an interactive visual environment. Visual analysis tools are software package act- ing as a toolbox and providing functionality to support the work of domain specific users such as data exploration, data analysis and data presentation. Such software packages still suffer from limita- tions such as restricted or imprecise data and problems with large data handling. These challenges will also be at the core of research in scientific terrain visualization in the near future. In this paper we describe some open challenges for scientific terrain visualization in the acquisition, processing and rendering of terrain related geo- spatial information as well as new methods which could be used to address these challenges.