Hornsby Council’s bushland field officer Stephen Pym made the discovery while walking on one of his favourite bushwalks.
The sandstone structure has steps carved into the surrounding rock, features several retaining walls and was built with bush rock and mortar.
Mr Pym said the structure is positioned underneath a rock overhang and has a small weatherproof room.
The site is located along a well-used walking track on the southern edge of land leased by Scouts Australia.
Access to the site is via Pomona Street, Pennant Hills near the Baden Powell Scout Camp.“My first thought was that the structures were formalised camping sites associated with the scout camp,’’ Mr Pym said.
‘‘However, isolated patches of spider plant and fishbone fern suggest attempts at gardening, while the rock work seems a little extravagant for an area to simply pitch a tent.’’
The Baden Powell Scout Camp opened in 1929 and was reportedly a permanent camp site for for people out of work during the Great Depression.“It would be interesting to know if these structures are associated with this harrowing time in our history or are the work of enthusiastic scouting groups.”
■ If you have any information about the structure contact 8867 2943.