What is the tower in front of?
The tower is in front of the bridge.
    src        edge_attr  dst
0     1               in    0
1     2           behind    5
2     2  to the right of   14
3     3           behind   14
4     3   to the left of    5
5     4  to the right of    9
6     4  to the right of   14
7     5   to the left of   17
8     5  to the right of    3
9     5      in front of    2
10    6  to the right of   14
11    8               in   14
12    8               in    3
13    9   to the left of    4
14   10               in   13
15   10      standing in   13
16   13             near   20
17   13             near   14
18   14   to the left of    2
19   14          next to   13
20   14   to the left of    6
21   14   to the left of    4
22   14      in front of    3
23   16               by   13
24   17  to the right of    5
25   18               on   19
26   20          next to   13
27   20           beside   13