Originally posted by Halfdan:

Maypole and Christmas Tree gives +1
Maypole is gone now, need to wait to another Midsommer to build it if you dont use consol commands :)

I believe it still spawns in the world randomly, its rare though.
My map only has a single one.

So if you find it, it might be an interesting location to build a forward resting base.
Although +1 probably is not worth much.