I saw it once, but I laged and I was kicked... BTW how did you get there? I don't remember. I don't think bad WiFi is needed for going there
Every time a new lobby is released I world download it to spectate all of the secret places. For example the hidden and blocked off office with a toilet in the new survival games lobby. Just saying I download the lobbies for looking purposes, nothing more.
You can download the entire hub here: http://www.planetminecraft.com/project/cubecraftgames-hub/ Edit: Woops! I thought you could download it. You can only look at it, no touching. xD
Its a mod, I'm not going to say the name of it. Considering I don't think Cubecraft would like all the users to download the worlds/lobbies, because they could use it for other "public" uses.