If we assume that learning is best achieved in a social setting, then a vital aspect of any learning environment is its ability to support the development of trust. Trust takes many forms, from helping to identify the validity or the effectiveness of a learning resource to feelings of safety and reliance on support from fellow learners and teachers. This article explores how the environment may support or diminish trust in several types of systems, situating them within a conceptual model of trust based on their social, cognitive, technical, interface and systemic features. It goes on to describe a learning environment called Dwellings, which uses a design based on Jane Jacobs's observations of what makes city districts thrive or decay. Dwellings may be thought of as a cross between a wiki, a moo and a learning object repository. It is built to enable trust to develop, through a combination of safety through a "succession of eyes," a fluid locus of control and social navigation approaches to collaborative recommendation. The article concludes with a discussion of issues that have arisen through the use of Dwellings and some thoughts on general features and future developments of learning environments that encourage the development of trust. (Contains 2 figures.)