San Francisco has oftenserved as a blank canvas since its rapid rise to prominence after the Gold Rush in the mid-1800s – the subject of countless visions for how the built environment should be designed. Whilesomewereoutlandish and others more grounded, the many ideas advanced over the years for guiding the City’s development have each presented a roadmap for moving forward, complete with nested values of what is most important for the future. Such is the subject ofUnbuilt San Francisco – an exhibit currently presented at five locations around the Bay Area, including at UC Berkeley (more details below). On display are plans, renderings, models, and other media depicting unrealized visions for the San Francisco Bay Area. Some of these proposals, such as a BART line running into Marin County, many wish had been built; others, like Marincello, a 30,000-person community in the now-preserved Marin Headlands, we cannot imagine advancing today. The exhibit covers a journey of great breadth, ultimately leaving the viewer with anuneasy sense of what could have been.