Fences are neglected heritage components of railway corridors. They record the development of colonial railways, they often contain components typical of earlier technology, they are usually considerably more robust than farm fences of similar age, and finally, they can provide accurate records of environmental changes in the adjoining landscapes. Four examples show the rich range of heritage information in railway fences. Massive fences built by the South Australian Railways in the late 19th century reflected British technology and practice, quite at odds with local farming practice. Droppers patented by Arthur Gatenby in Tasmania in 1888 were widely adopted by farmers and railways in various states, and are the most widespread and abundant dropper in railway fences. In a vain attempt to stop the eastward advance of rabbits, the New South Wales government built 655km of rabbit-proof fence across the state in the 1880s, primarily by hanging netting on existing railway fences. Buried railway fences in northern South Australia record the history of failed northern expansion of cultivation beyond Goyder's Line in the 1870s. Finally, the almost insuperable problems of conserving these fences are addressed, concluding that detailed recording is perhaps the only feasible approach.