Hornsby Heights is a suburb of Northern Sydney, in the state of New South Wales, Australia. Hornsby Heights is located 26 kilometres north-west of the Sydney central business district, in the local government area of Hornsby Shire. The suburb is often referred to as part of the Upper North Shore.

Galston Gorge is a valley located in the Berowra Valley Regional Park in Sydney, Australia. It separates Galston from Hornsby Heights, and is intersected by Galston Road and the heritage-listed Tunks Creek Bridge at the foot of the valley. Adjacent to Tunks Creek Bridge, there is a second concrete bridge that crosses Berowra Creek. The gorge itself contains many walking tracks, waterfalls and a variety of Australian flora, and is an area frequented by hikers, cyclists and rock climbers.