urban space

   0   1   2   3   4   5   6   7   8   9  10  11
                                               
11             S---S   S---S---S---S---S---S     11
               |   |   |   |       |               
               |   |   |   |       |               
10     S---S---S   S   S---S---S---S-str1-rts2   10
       |       |   |   |       |   |       |       
       |       |   |   |       |   |       |       
9  S---S---S   S---S---S---S---S   S---S   R---R  9
   |   |   |       |   |   |   |   |       |   |   
   |   |   |       |   |   |   |   |       |   |   
8  S  stu1 S---S  cts2 S  cts1 S---S--str2-R   R  8
   |   |           |       |           |       |   
   |   |           |       |           |       |   
7  S   U---U--ctu2-c---c---c---c   R--rts1-R---R  7
       |   |       |   |   |   |   |           |   
       |   |       |   |   |   |   |           |   
6  U---U   U---U   c---CCCCC---c   R---R---R   R  6
   |   |       |   |   C   C   |   |   |   |   |   
   |   |       |   |   C   C   |   |   |   |   |   
5  U   U---U---U   c---CCCCC---c   R   R---R---R  5
   |       |       |   |   |   |       |   |       
   |       |       |   |   |   |       |   |       
4  U---U   U--ctu1-c---c---c---c--ctr1-R---R---R  4
   |   |   |           |               |           
   |   |   |           |               |           
3  U  sew  U---U---U  ctu4 U   R---R---R---R      3
           |       |   |   |   |       |   |       
           |       |   |   |   |       |   |       
2      U---U---U   U---U---U   R---R   R   R      2
       |   |           |       |   |       |       
       |   |           |       |   |       |       
1      U   U---U---U  cli  R---R   R   R---R      1
           |   |   |           |   |   |           
           |   |   |           |   |   |           
0          U---U   U---U-ur-ru-R   R---R          0
               | 
   0   1   2  pla  4   5   6   7   8   9  10  11

S = slums
U = urban
R = residential
ctu = tunnels from Citadel to urban space
cts = tunnels from Citadel to slums space
ctr = tunnels from Citadel to residential space
str = transition from slums to residential
rts = transition from residential to slums
stu = transition from slums to urban
ur-ru = transition from urban to residential
c = courtyard of Citadel
C = Citadel
cli = clinic
sew = entrance to underground sewer