Newnham is fortunate in having its own sports field on the main site. Students regularly play hockey, football and lacrosse and use the tennis courts at the far end of the field. At the far end of the playing field is the Observatory, housing a telescope that can be used by students for sky watching. Around the Observatory are borders of Newnham's unique collection of bearded irises.
The first four Newnham Irises are named Henry Sidgwick, Anne Jemima Clough, Old Hall and Peile Hall. The iris collection was developed as a collaborative project between the Garden Committee and British Iris breeders Barry Emmerson, Simon Dodsworth and Gary Middleton. The iris borders contain irises from the Newnham Collection, as well as many named varieties that were donated by the breeders.