Lunar: Eternal Blue—Zaback Mine

B4–B

        /---\
To B3-B |----\
   @    |    v     /\  
   \----+  /---\  /..\.
        |  | ^ |  |  | To Marius Zone
        \v | | |  |  |  @
      /----/ | \--+--+--/
      |  ^   |    |
      |  |   |    |
      |  |   |    |
      |  |   |    |
      \--+---+----+

B3–B

          To B4-B
              @
              |
              |       To B2-B
     /---\    |  /--\   @
     |   |    |  |  |   |
     |   |    |  |  +-\ |
     \-->|<---+--/  | | |
         |          | | |
         |          \-+-/
         |            |
         \-+--\       v
      /--\ |  |    /----\
      |  | |  |    |  ^ |
      |  \>|<-+    |  | |
     -+    |  |    |  | |
      |    |  +--->|<-+-/
      |    |  |    |  |
      |  /-+..+    |  |
      \--/  ..+    |
              +----/
              |
              |

B2–B

               To B1-B   To B3-B
    To Black     @       @
Dragon Cave @    |       |
            |    |       |
            v   /+---\   |
         /----\ |    | /-/
         |  ^ | v    | |
         |  | \---\  | |
         |  |   ^ |  | |
         |  |   | |  +-/
         \...   | |  |
          ...---+ \--/
                |
                |
               ...
               ...

B1–B

               @ To B2-B
               v
             /---\  
          /--+ ^ +- | .
          |  | \-/  | |
          |  |        v
          |  |      /---\
          |  v      | ^ |
          +----\    | | |
          |  ^ |  /-+ +-/
          |  | |  | | |
          |... \->|<+-/
          \...    |
             \----+-
                  @
          To Mine Entrance