And the Winner is
Defence of Perth
Adventure Lab Series.
This series has 5 stages and is located from Fremantle through to Bull creek. Focused on local military sites including Tunnels, Telecommunications, Spitfires, Tanks and Artillery.
Congratulations to Meme28 who started Geocaching in 2018 and has found over 2200 caches, they have another Lab series called Colonial Northbridge for you to complete also.