It is impossible to return to this orcish prison, even if you build stairs up to the entrance.
Killing the Orc Jailor Edit
It is possible, though ulitmately worthless, to kill the orc at the beginning. But for those brave pre-game champions, here is how to do it:
First, either run past the orc or hit him to wake him up. If you decide to hit him, position yourself as far away from him as possible and be prepared to run away. Now the real fight begins: To kill the orc we employ a hit-and-run tactic were we hit the orc between his attacks. However, due to the fact that the orc can potentially kill you in one hit, it is important to know the orcs attack pattern. The orc will start his attack of by swinging both of his arms at the same time and after that, he will hit with his right arm slightly more frequently than with his left one. Because of that, the swings of his left and right arm will get out of sync after about five hits. A at this point, you need to follow the path until your just past the upper bend, where the orc will stop chasing you. Here you can also heal if the orc got a hit on you. After a few seconds the orc will turn around and go back inside the prison and walk against the bottom-right-hand wall. When the orc walks back to the prison you need to follow him closely and, after he went into the cell, position yourself at the bottom wall, just to the left of the prison door. The orc will now come after you again, but his attack pattern will have reset, allowing you to savely get a few hits in, before his arms get out of sync again. Now just repeat this process until the orc is killed.
Upon death, the orc will drop the same amount of gold like any other orc.
Also note that this orc is special in that he can not sprint and does not spawn weapons. Both the orc and the bat will never respawn.