What is the lake surrounded by?
The lake is surrounded by the mountains.
    src        edge_attr  dst
0     0   to the left of    6
1     1   to the left of   15
2     1  to the right of   22
3     1   to the left of    8
4     1   to the left of   21
..  ...              ...  ...
88   22   to the left of   15
89   22   to the left of    8
90   22   to the left of    1
91   22   to the left of   13
92   22   to the left of   12

[93 rows x 3 columns]