Signposted 5km inland from the Huon Hwy 15km south of Dover are the amazing Hastings Caves & Thermal Springs . Explore the caves via guided tour: buy tickets at the visitor centre. Tours leave roughly hourly, but times vary through the year: call of check the website for specifics. Admission includes a 45-minute tour of the amazing dolomite Newdegate Cave , plus entry to the thermal swimming pool behind the visitor centre, filled with 28°C water from thermal springs.
There’s a decent cafe (mains $10 to $20) at the visitor centre, which also sells barbecue packs and picnic hampers.