Delivering large scale public engagement open weeks at STFC

The Science and Technology Facilities Council (STFC), part of UK Research and Innovation (UKRI), has a rich tradition of fostering public engagement and outreach, as part of its strategic aim to showcase and celebrate STFC science, technology, and staff, both within its National Laboratories and throughout the broader community. As part of its wider programme, STFC organised two large scale public engagement open weeks in 2023 and 2024. These events, held at the Sci-Tech Daresbury campus in the North of England and the Harwell Campus in the South of England, home to STFC's largest National Laboratories, collectively welcomed over 17,500 participants. These open weeks provided an unparalleled opportunity for the public to engage intimately with groundbreaking science and technology. Attendees were immersed in hands-on activities, demonstrations, and enlightening talks spanning various disciplines and catering to all age groups. They also had the unique opportunity to explore the state-of-the-art facilities on site, and talk with the people who work here. Scientific Computing (SC), a department within STFC, took a lead in orchestrating and delivering computing outreach initiatives during both open weeks. This paper details STFC's approach to organizing these open weeks, how the open weeks were structured, SC's planning process for contributing to the events, and delves into the specifics of SC's impactful contributions. By sharing these insights, this paper aims to offer valuable lessons for the effective execution of large-scale public engagement initiatives within the scientific community.