▁key ▁phases ▁in ▁the ▁history ▁of ▁Royal ▁National ▁Park ▁including ▁Ab original ▁occupation , ▁past oral ism ▁and ▁agricult ure ▁but ▁particularly ▁recre ation ▁uses ▁that ▁started ▁in ▁the ▁ 1 9 2 0 s , ▁continued ▁during ▁the ▁De pression ▁period ▁and ▁intens ified ▁during ▁and ▁immediately ▁after ▁the ▁Second ▁World ▁War . ▁ ▁The ▁cab ins ▁are ▁significant ▁for ▁their ▁continu ity ▁of ▁use ▁for ▁over ▁fifty ▁years . ▁The ▁cab ins ▁provide ▁evidence ▁of ▁the ▁development ▁of ▁simple ▁week ender ▁accommod ation ▁around ▁Sydney ▁from ▁the ▁ 1 9 2 0 s ▁and ▁ 1 9 3 0 s , ▁starting ▁with ▁tent ▁accommod ation ▁and ▁developing ▁into ▁h uts ▁and ▁cab ins . ▁The ▁cab ins ▁also ▁reflect ▁the ▁emb rac ing ▁of ▁Sydney ' s ▁bush ▁hinter land ▁in ▁the ▁early ▁part ▁of ▁the ▁tw enti eth ▁century ▁and ▁the ▁reci pro cal ▁role ▁the ▁bush ▁had ▁in ▁the ▁development ▁of ▁recre ation ▁and ▁conservation ▁philosophy ▁in ▁NS W . ▁The ▁rapid ▁growth ▁in ▁cabin ▁numbers ▁from ▁the ▁mid - 1 9 4 0 s ▁reflect ▁important ▁social ▁and ▁work place ▁re forms ▁in ▁NS W ▁at ▁that ▁time ▁that ▁provided ▁more ▁le is ure ▁time . ▁ ▁The ▁cabin ▁communities ▁are ▁histor ically ▁significant ▁in ▁demonstr ating ▁links ▁between ▁Sydney ▁and ▁the ▁Il la war ra , ▁in ▁particular ▁the ▁northern ▁Il la war ra ▁coal ▁min ing ▁town ▁of ▁Hel ens burgh ▁and ▁southern ▁Sydney ▁sub ur bs . ▁It ▁was ▁Hel ens burgh ▁min ers