If you're trying to add the look of an entrance to an already made map then you will have to remove the part of the wall that is already there first.
Here's a link to an edited version of MW. I've added new caves at co-ords: 565:504 and 950:401. I couldn't do co-ords 55:637 as the only cave entrance I have that matches that style of wall is on a corner angle and I would of had to completely re-do that section of the map in order to make it fit right. Of course you could put the door just down from those co-ords and have it so you dont actually see the door you just see the top of the wall above where the door would be. However, if you decide to put the door somewhere else then I don't mind adding that one too.
Edited MW map
If you haven't already sorted anything else out I'll do what I can with the other two maps tomorrow when I get in from work
