In this study, we describe how to keep a campus safe and “open” by implementing a proactive, as opposed to reactive, strategy (the Green Zone strategy). The pillars are leadership, clear communication, clean air, vaccination campaigns, and intense efforts in mass testing. Over a period of 12 months, about 277,000 pooled real-time polymerase chain reaction (RT-PCR) samples and lateral flow tests (LFTs) were collected, and 201 people were identified as COVID-19-positive. For the PCRs, we use the Lollipop technique, combined with nose swabs and gargle samples, to minimize sample-collection efforts. Importantly, not only staff, students, and contractors, but also their family members, friends, and partners; daycare centers; and local sports and arts teams, etc., were invited and participated. This outreach made it possible to propagate the tests more widely and monitor a larger network. At times of larger social gatherings—most prominently, on 23 December 2021 before Christmas (during the rise of the Omicron wave)—testing capacities were increased. The results not only demonstrate the great power of mass testing in providing an open-but-safe work environment, even if the surroundings are highly infectious (red zone), but also the strength and resilience of a university. It shows how the unique pillars of science, infrastructure, students, and independency make it possible to maneuver a community, even through unpredictable times.