The Australian Botanic Garden sits at 362 Narellan Road, Mount Annan — part of the Botanic Gardens of Sydney network alongside the Royal Botanic Garden in the city and the Blue Mountains Botanic Garden. At 416 hectares it's the biggest of the three, and Australia's largest botanic garden by living collection, holding more than 4,000 native and introduced plant species. The centrepiece is the Connections Garden, a 4.5-hectare "roofless museum" built around how people and plants intersect, backed up by a Dry Country Landscape, the Banksia and Grevillea Gardens, and a Conifer Arboretum.
There's enough ground to fill a full day out. Five lakes are scattered through the site, a Wollemi Pine collection is reached via the Wollemi Discovery Walk, and the Stolen Generations Memorial sits within the grounds. More than 20 kilometres of walking tracks — the Central Valley, Woodland and Wollemi walks among them — wind through the garden, alongside dedicated mountain-bike trails and roadways popular with road cyclists.
Tucked into the site is the Australian PlantBank, the seed bank and plant science building that opened in 2013 and now holds around 10,000 seed collections representing more than 4,500 species. For a lower-key visit, there's a Garden Cafe and a Garden Shop, plus ample on-site parking — it's an easy run out from Menangle Park along Narellan Road, and no booking is needed to just turn up.
Good to know: open daily from 8am; closes at 5pm through the standard-time months (April to September) and 7pm during daylight saving (January to March, October to December). Entry is free except for special ticketed events, and on-site parking is free.