>>789604These are coalers huts. As the charring coal pile needed near constant tending for days on end, these were built adjacent so the coalers could work in shifts.
You often find remains of the hearths scattered troughout the forrests of mid and south sweden, usually with a crater nearby from the pile. Tar - a byproduct from making charcoal primarily from pine - was once swedens biggest source of income in terms of exported goods
>pic related, one in construction for some open air museum 
