Now, I’m clearly biased here as I’m a bit of an (unofficial (for now)) archaeologist, but I thought it may be a nifty mechanic to include. Doesn’t have to be anything big, it’s mostly something to have so there’s a reason to go to rural places when looking for ways to get money other than just farming carrots or something.
First things first is to head to a store and make sure you got the right(?) tool for the right job. You probably shouldn’t try to excavate incredibly fragile material with nothing but shovels and brushes, but I’m not your mom, I won’t stop you.
Bring those tools over to some sites and dig up some wonderful trinkets, baubles, odd doodads and whatchamacallits. Sell it to a museum maybe, or pawn it off. It’s not really anything exciting, just a nice way to make some cash on the side. Unless of course, you want to make it exciting. Dig up the ancient lost book of the dead looking for old instruments or something. That’d be pretty cool.