A 7.5km drive inland from the Southport turn-off on the Huon Hwy are the amazing Hastings Caves and their adjunct thermal springs. Cave tours (45 minutes) take you into the impressive dolomite Newdegate Cave, with the option of a dip in the thermal pool behind the visitor centre, filled with 28°C spring water. Tour times change across the year (check the website), but there are at least four tours a day.
The visitor centre cafe sells toasted sandwiches and pies (items $4.50 to $7).
There's a good chance of spotting a platypus on the 10-minute Platypus Walk behind the pool, while the wheelchair-friendly Hot Springs Trail does a big loop from the pool area, taking 20 minutes to navigate (the pool is also wheelchair accessible).
Note that the cave entrance is a further 5km drive beyond the visitor centre. No public transport runs out this way.
