What is on the wall that is made of concrete?
The street sign is on the wall.
   src        edge_attr  dst
0    0             near    5
1    1  to the right of    9
2    2  to the right of    4
3    4   to the left of    2
4    5      in front of    9
5    5             near    0
6    9   to the left of    1
7   10               on    9