I couldn't see a better fit for this in the other forums, and this is "harvesting" of a sort.
I've recently been looking into some of the history of Australian gold mining, ahead of a family trip in Australia. We will be heading to some of the old gold fields and visiting some of the tourist sites where you can do some gold panning. My five year old is very much into finding "treasure" - mostly fossils, shells and sea glass on our beach trips - so I searched for some videos of gold mining and panning. The upshot of it is that I realised that gold is FAR more common in the landscape than I realised. Here in the UK there are many locations where you could go panning for gold in streams and rivers. The quantities are very much in the "commercially non-viable" category, but for a fun activity day it could be well worth it.
Some of the areas where traces of gold have been found are regions where I go hill walking anyway, and messing around in a stream on a hot day while out walking is simply fun. I think a gold pan is going to be added to my regular walking kit from now on.