The Tarkine contains a number of unique cave systems. Some of these, such as the magnesite karst systems that exist in and around the Lyons River, are globally unique (Sharples 1992b; Sharples 1997; Houshold et al. 1999). The Tarkine contains extraordinary magnesite karst systems, including unique cave and pinnacle formations at Lyons River and the Arthur River - Victory Springs area, with the hydrothermal karst hydrology including warm springs in pristine condition. This mostly undisturbed magnesite karst area is a high priority for protection of its karst values, since no magnesite karst is currently represented within any Tasmanian conservation reserve of declared World Heritage.
The Tarkine also contains dolomite cave systems in the Trowutta/Sumac/Black River region which features hundreds of sinkholes (including the outstanding sinkhole, Lake Chisholm), and karst landforms in the 'Ahrberg' group - which exhibit karst landforms including decorated caves and underground drainage, which (as they are studied more extensively), are likely to be of considerable aesthetic, geomorphological, archaeological and biological interest.
These cave systems are not only unique in themselves, but are also home to extraordinary cave dwelling creatures, such as the bizarre 'troglodyte' (cave dwelling spider) and other fascinating creatures.