Ungriefable.

Check the OP for coordinates.

server?

The awkward moment when there's nothing there and there's a sign that says ICC LOL

SMP 2, sorry.

If you find this, tell me. I'm curious but with no time to go there

from what i see, theres nothing on the live map.

I hate to burst your bubble(pun intended for those of you that found it ), but if someone used an aqua affinity/respiration helmet and an efficiency V pickaxe they could most likely get through that .
Edit: It is a pretty good idea though since almost no griever would even want to go to the extent to break into it

under water?

could also drop gravel in a 3x3 square, mine out the middle, then place ladders

all of which takes time. And I doubt you would leave your house unattended for very long, or share the coords. Plus, you can always build much, much deeper.

It takes over 4 minutes to break into a block of obsidian underwater. you are welcome to try.

Also, I would like to point out that the doorway also acts as an ungriefable way to lock your items. I've built something like 25 blocks deep underwater before. This was just a simple, quick thing. And of course anything can be broken eventually in minecraft. The question is, can you do it without dying, fast enough to not get caught, and are you willing to accept the chance of losing items as valuable as what you point out in order to get in there?

Even with all of those enchantments? Well I guess I learned something new today

With all of them? I have no idea. I feel as if you'd still drown first though

You could always make artificial air. Not exacly hard to do. But even then, time is your enemy.

Nabs figured a way out, but I know how to counter it with a better build. *shrug* I also would like to point out that it is very easy for the original builder to get in and out of the structure.

We will just make it so there is no water where the obsidian is like cobblestone area covered with signs and a ladder

BTW we must get all of EMC's best griefers and their king: Lord Herobrine

So it's an obsidian entrance underwater?
THAT'S ungriefable?
*facedesk*

i believe you mean lord jlopez!!

No, its a small version of an easily creatable bigger building underwater. I have no need of a full scale building on a server I don't play on.