A simple map I myself find useful.

Ground level

                          11                  Key to symbols
                           |                  + Map 19 is placed inside map 18
        26  ― 28          10
         |
  29  ―  9  ― 18+
         |     |                                            N
  31  ― 14  ― 16    34     3                            NW  |  NE
         |        \  |     |                              \ | /
        32          15  ―  1  ―  7                    W ――― O ――― E
                                    \                     / | \
                                      24                SW  |  SE
                                                            S


Underground level

                          12²                 Key to symbols
                                              ² These maps have second levels:
        27     ·           ·                      11→12, 4→17, 2→5
                                              · Maps without underground levels
  30     4² ― 35

   ·     ·     ·     ·     6

         ·           ·     2²   22

                                      25

World maps

• Argaes (Geography)
• In-game world map
• Superkoop’s in-game world map

Map development

• Map development (Mapping tutorial)
• Content development forum
• Open map development tickets in Mantis (all map development tickets)