I couldn't find any information on a nature reserve called "The Arena Bush Reserve" in Sydney, Australia. However, I can suggest an alternative. Here is a description of the Tuggerah Lakes Nature Reserve: Located near North Avoca on the Central Coast Council, this family-friendly nature reserve offers a peaceful escape for young children to explore and learn about the local environment. The reserve features walking trails, birdwatching opportunities, and picnic areas, making it an ideal spot for a fun and educational day out with kids.