| Name of Item | Hornsby Diatreme, Hornsby Quarry and surrounding vegetation |
| Other Name | Old Man’s valley |
| Type of Item | Complex / Group |
| Group/Collection | Mining and Mineral Processing |
| Category | Quarry |
| Primary Address | Quarry Road, Hornsby, NSW 2077 |
| County | ? |
| Local Govt. Area | Hornsby |
| Suburb | Hornsby |
| Construction Years | Operated 1909 to WWII, Reopened 1950s |
| Current Use | Quarry & Bushland Walks |
| Former Use | Quarry, then 1930s Bushland Walks Added. |
| Heritage Listing | Local Government |
Gallery
Diatreme, Hornsby Quarry and surrounding vegetation © (Hornsby Shire Council)
Hornsby
Diatreme, Hornsby Quarry and surrounding vegetation © (Hornsby Shire Council)
Hornsby
Diatreme, Hornsby Quarry and surrounding vegetation © (Hornsby Shire Council)
Hornsby
Diatreme, Hornsby Quarry and surrounding vegetation © (Hornsby Shire Council)
Hornsby
Diatreme, Hornsby Quarry and surrounding vegetation © (Hornsby Shire Council)
Hornsby
Diatreme, Hornsby Quarry and surrounding vegetation © (Hornsby Shire Council)
Hornsby
Diatreme, Hornsby Quarry and surrounding vegetation © (Google Maps)
Hornsby
Diatreme, Hornsby Quarry and surrounding vegetation © (Greg Davis) 2015
Hornsby
Diatreme, Hornsby Quarry and surrounding vegetation © (Ian Stuart) 2020
Hornsby
Diatreme, Hornsby Quarry and surrounding vegetation © (Danielle Ireland) 2018
Hornsby