Is there a clock tower that is not made of brick?
No, there is a clock tower but it is made of brick.
   src        edge_attr  dst
0    3        on top of    4
1    9  to the right of   12
2   12   to the left of    9
3   12               in    1
4   13        on top of    4
5   13               in    4
6   14               on   13