I have multiple things floating around.
Trees seem to be floating at higher elevated levels.
Like a mountain wich is higher than my grass level. The tree should be on the rocks but is floating just besides it.
After accepting a trade the materials get dumped with your banner.
Somehow they just as often end up ontop of the banner and never get hauled away.
Also the leaves of the tree are often inside the mountain when the tree is growing to close to a vertical wall.
Welcome to the forum, @Semmy! And thanks for reporting. 
About items dropped on top of things: try moving the banner or whatever is under the items. They should fall to the ground and your hearthlings will pick them.
Trees are not really floating (unless they’re on top of another tree). There’s at least one voxel that’s in touch with a part of the terrain. It looks bad, yes…
And trees clipping with the mountain is a side effect of the world generation too.
These issues are known, but we don’t know when will get fixed.
Which version are you running, Alpha 8, I suppose?
I was running the latest dev build.
Wanted to try out the blacksmith.
And yes indeed 1 voxel touching it.