https://en.wikipedia.org/wiki/Menhir
Like boulders, but larger. I think they should require a special cartlike object to move them around, which can only be pushed by 2+ hearthlings. Or the object could be dragged by a bull, a la wagon. We should also be able to carve runes on them. Maybe this is hard to implement but could be an idea for future worlds?
This is "important" for artworks/hearthling built druidic temples and such.