Project-based learning (PBL) is centred on a challenging, yet meaningful, driving question and culminates in a product that students create or do to showcase their learning to a public audience. Other essential elements of a true PBL experience include: sustained inquiry, authentic tasks, opportunities for students to make decisions about their culminating product, reflection, critique, and revision (Hallermann, Larmer, & Mergendoller, 2011). A well-designed PBL combines curriculum and instructional activities to cultivate 21st century skills in students to prepare them for future success in the workforce. Two teams of Year five teachers designed a week-long PBL unit for students organised around the characteristics of the planets, which integrated science, mathematics, and English. The teachers implemented the PBL with six classes of Year five students, documenting their thoughts on planning and implementation to reflect upon the experience.