An upside-down mountain, formed from dust. The whole thing is about the size of a single bacterium.
The mountain is, as usual, not supposed to be there - it’s a piece of dust that landed on my sample. Despite doing all my processing work in the cleanroom, it’s still hard to avoid the occasional piece of dust. The long thin line in the back is the structure I was trying to make - in this case, the dust is fortunately just far enough away that it shouldn’t affect things. But the ground is still noticeably fluffy - I’m still working on how to solve that one.