@Jaxilon: I was wondering how to give some depth to the rocks so I'll try it out and see what happens even though I'm almost sure that it would look better that way.

@geamon: To answer your question I'm doing "a relatively accurate replica".I decided to add rubble to the northern and west sides of the map because in the encounter's flavor text it said that those sides "are impassable due to high piles of unstable rubble".
For some reason wizards decided not to map those those sides (possibly because they didn't have the right Dungeon Tiles)so instead of having to explain to the player's what's surrounding them I decided to show it to them.