The Salmon Ponds, established circa 1860, is the oldest trout hatchery in the Southern Hemisphere. It's about 45 minutes drive up the Derwent Valley from Hobart, on the western side of the river. Drive in through the spectacular drystone walls on either side of the entrance and it's like entering a Secret Garden.
It's been a popular spot for family picnics since the late 19th century. The grounds are laid out like a classic English country garden. You can visit the wonderfully rough-hewn old building that housed the Trout Hatchery, the centre of the original operation.
The Hawthorn Arch was the original entrance in the 19th century. The old Keeper's cottage, built in 1865, now doubles as the Museum of Trout Fishing and as the Tasmanian Angling Hall of Fame. Even if you aren't a fisherman, there's a lot of interesting stuff about the problems of transporting trout and salmon eggs out from Britain 150 years ago (i.e. before refrigeration).
They actually encourage you to feed the fish, who are always happy to see visitors. If you want to feed yourself, there's a barbecue area or you can visit the restaurant (tweely titled Pancakes By The Ponds).
There's a lot of bird life around, including the Superb Blue Wren (first time I've seen one in real life – they are superb!) and the occasional sinister-looking raven.
On the way home we called at St Matthew's Church in New Norfolk, built in 1824. I've never seen a church this size with so many stained glass windows.