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Spatial reasoning is a fundamental part of human cognition, playing an important role in structuring our activities and relationships with the physical world. A substantial body of spatial data is now available. In order to make effective use of this large quantity of data, the focus of GIS tools must shift towards helping a user derive relevant, high quality information from the data available. Standard GIS tools have lacked focus in this area, with querying capabilities being limited, and requiring a user to have specialised knowledge in areas such as set theory, or Structured Query Language (SQL). A fundamental issue in standard GIS is that, by relying entirely on numerical methods when working with spatial data, vagueness and imprecision can not be handled. Alternatively, qualitative methods for working with spatial data have been developed to address some key limitations in other standard numerical systems. TreeSap is a GIS application that applies qualitative reasoning, with a strong emphasis on providing a user with powerful and intuitive query support. TreeSap's query interface is presented, along with visualisation strategies that address the issue of conveying complex qualitative information to a user. The notion of a relative feature is introduced as an alternative approach to representing spatial information.