There's no way to view this in-game as it has been deleted, and probably will not be added back into the game in the near future, as it has been removed from the game either partially or entirely.
This is a secret island far away from the main map that you can only access with bugs and glitches (an admin can teleport you to here too). This island is mainly used by developers and contains some W.I.P models. This island gives hints for new stands and items. For example, Ratt, Red Aja, and Ultimate Life Form (ULF). This could be jumped by simply holding x and not letting go to use the freeze glitch to do cool down and a C-Moon. There is also an NPC inside the cabin, The Interrogation Man.
A sign sitting on the grass. This is not in the game's original map. You can find it if you made a bug. However, it's really hard to find and visit because it was intentionally placed behind the invisible walls of the game.
A man inside the cabin placed on TORNADO98765's And Denzee's Soviet Island. There seems to be nothing incredibly suspicious or interesting about him. We don't know if he is a reference or based on a real Roblox character.