On the info for when a adventurer dies, it should include what it died to and perhaps even the X/Y coordinates so you can approximate where (if adventurers are dying frequently in the same spot you can know to put a bonfire there) Oh. Or a temporary marker where they died would be fine as well, that when you click on the info message it shows you the spot. Basically anyway that leaves info you can find to suggest good places to build a bonfire when your peoples are dying a lot around there