What are these giant holes?

[atdfbttl15]

Hi ladies and gentlemen,

I wanna ask you something: I encounter with giant holes at the East Town like this:

(click to show/hide)

What are these? Are these homes or giant mines?

[SalasCraft]

It's griefed to the ground. Literally.

[Zen00]

I would say they are griefs, though they are a bit weird. Could be mines as well, but not orderly enough for that, unless someone was mining willy nilly all over.

[atdfbttl15]

Then if they are not homes or mines, we should cover it right? Because it is deadly.

[SalasCraft]

Then if they are not homes or mines, we should cover it right? Because it is deadly.

I think it's done by people who go gather sand and just suck it all up.
You should let an operator or moderator undo/regen that area to save you all the trouble.

[Xeadin]

If it's East town, Regen will not function properly. If we do, then that part of East Town will become an Ocean (literally, that is what the current world seed is set to for that specific area)

[atdfbttl15]

If it's East town, Regen will not function properly. If we do, then that part of East Town will become an Ocean (literally, that is what the current world seed is set to for that specific area)

No need to regenerate. Can you just use your world edit to fill that hole with sand?

[Smiteme69]

When east town gets bad , someone has to cuboid sand in I believe.

 Just a note to whoever does this sand replacement, please don't cuboid over my bridge to my house
 
 I lost most of my bridge and 3 coal PS my bridge literally connects to the spawn area.