We’ve heard a lot about the greenhouses that grow fresh produce, but are there areas where these growers set up a market? Like the farmer’s markets in a lot of other European countries? Or will we need to get our produce only at the grocery store?
No, farmer's markets like in other European cities are not a thing in Iceland. You can buy produce in the grocery stores, but also at random roadside stands. We also had an opportunity at one campground as the host had a bunch of heirloom tomatoes for sale.
There is no such thing in Iceland unfortunately. The only exception is Fridheimar for the tomatoes (around the Golden Circle)