This is the bonus cache for the "Avon Venture: Part V - A hospital pass" adventure lab, which takes you along the lower reaches of the Hagley Park / Botanic Gardens section of the river, past Christchurch Hospital, and along the initial part of the CBD section of the river. When you complete the adventure lab you will be given the coordinates of this cache, and a picture of the tree/shub that the small plastic container is at the base of (under a stone). Please leave well covered (the cache has been muggled once).