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.

Galston is a semi-rural town located in the Hornsby District of Sydney, in the state of New South Wales, Australia. Galston is located from the city at 36 kilometres north-west of the Sydney central business district, in the local government area of the Hornsby Shire. Galston is in the NSW state electoral district of Hornsby and Federal division of Berowra. Galston is situated 16 minutes away from the suburb of Hornsby.