What is on the building the sky is behind of?
The sculpture is on the building.
   src        edge_attr  dst
0    0               on    2
1    0  on the front of    2
2    1           behind   11
3    2        on top of   11
4    3               on    0
5    6               on   11
6    7               on    2
7    9        on top of    2