MAP OF THE SEWER (Level 1)

     |----------|--------|-----------------|
     |          .        |           ^     |
     |-|        .        |----|----| |     |      A : Up to Dump
  |    |        .        |    C    |-|     |-|    B : Old Well
  |----|        .        |           |     |-|    C : Barrel
  |    |-----------------|           |     |      D : Shaft (to lvl 2)
  G    |        .      B-|-|         |     |      E : Down to lvl 2 (falling)
       |     |------|------|         |     |      F : Down to lvl 2 and 3
       |     |      |         D      |     |      G : Down to lvl 2 (no way up)
     F-|-----|    E-A-        |      |     |
       |     |      |         |  |   |     |      ^ : one way passage
       |-----|----------------|--|---|-----|      . : virtual tunnel