Heritage Open Day: Celebrating over 250 years of the Radcliffe Observatory, the college together with the University of Oxford Astrophysics department will be offering historians on hand to answer questions and activities including a family-friendly garden trail. Celebrating over 250 years of the Radcliffe Observatory, the college together with the University of Oxford Astrophysics department will be offering historians on hand to answer questions and activities including a family friendly garden trail. Engage with passionate researchers, explore the universe through interactive activities like an infrared camera and a solar system model, and enjoy hands-on crafts perfect for kids.