How can one use new technologies available on mobile devices to communicate significant historical information? Augmented Reality apps such as Aurasma make it possible to overlay video in a scene viewed through the camera of a mobile device. Historical figures can appear present in locations where they achieved something significant. Designing Downtown is a mobile augmented reality tour of downtown Atlanta in which two significant 20th century architects are represented when the buildings they designed are viewed through the camera of a mobile device. Their thought processes and personalities are communicated so that viewers can learn how and why they designed these buildings and what they felt they achieved. This project was designed to support historic preservation in the city of Atlanta.