Hastings Caves is a 90 minute drive from Hobart in the Huon Valley. Hastings Caves is a natural dolomite cave system formed millions of years ago. Guided tours are available from a Parks and Wildlife guide and you can relax in the heated thermal springs reserve. There are picnic and barbeque facilities in the area allowing for a perfect day trip.
Parks and Wildlife Service Website for Hastings: https://www.parks.tas.gov.au/index.aspx?base=4525