Sydney’s newest bushland park in Hornsby, on the city’s upper north shore, has been created at the site of an old quarry abandoned since 2003. The 60 hectares is a peaceful retreat just 10 minutes on foot from the local train station, which will eventually service 6,000 new homes.Hornsby Park sits atop an ancient volcano on Dharug and GuriNgai country. The former industrial site has been revegetated with the quarry walls stabilised.“We’ve got to get more [housing] density into that space [around the train station],” says Glen Magus, the acting general manager of Hornsby Shire council.“And right in our back yard in Hornsby we’ve got this 60-hectare site that’s really a blend of nature, history and culture. It’s a rare moment for council to actually get an opportunity like that … something that we can provide liveability for our community.”Guardian Australia visited the park last week. I’m a denizen of the inner city, more used to plane trees than eucalypts. But it won me over immediately.A highlight is Hornsby’s heritage steps, which stretch for about 1km, connecting Hornsby pool at one end and the Great North Walk at the other. Constructed in the 1930s, the stairs are steep in parts, but provide perfect access for a sun-mottled walk through fern groves and blue gums that grip the volcanic soil. Lorikeets, rosellas and kookaburras are flitting about when I visit.The first stage of Hornsby Park opened in March. The main attraction is, of course, the old quarry itself. A remnant of its working history remains in the form of an old crusher plant, fenced off from would-be climbers. Then there’s a new red metal viewing platform that’s stunning – even in a city famous for its vistas.Hornsby Park’s old quarry. Photograph: Blake Sharp-Wiggins/The GuardianThe viewing platform. Photograph: Blake Sharp-Wiggins/The GuardianJutting out 14 metres above the ground below, the 42-metre-long platform draws in visitors who can then look down to the turquoise water filling the lower level of the quarry.“Oh wow, this is lovely,” a woman says. “One day, you might be able to swim in it?”One day, perhaps. But for now, Hornsby council says: “The quarry void and lake are not currently accessible to the public. Any future consideration of swimming would require careful assessment of community safety, access and funding, including advocacy to state and federal governments.”