Over the past few years, there has been a growing trend in the use of primary documents, those original historical documents used by historians, to teach history in high school and even elementary classrooms. This article uses the author's experience of designing a web-based history education project, The Great Unsolved Mysteries in Canadian History project (www.canadianmysteries.ca) to explore some of the promise and problems of using primary documents to teach history. The article suggests that this approach not only makes history more interesting to students, but it does so by drawing students into the processes of critical and imaginative thinking needed to 'do' history.