It's not as if climbing mountains is easy - but there you go, the Oputians have to push the boundaries and thought it would be a good idea to offer giant outdoor chess games as an amusement. Not in the park, not by the river, not anywhere sensible but up a mountain instead. It all went surprisingly well for a bit, was very popular but it was all ruined by the last major earthquake which caused so much damage that games became impossible. Still, the ruins of the board and the pieces are still there and have become a bit of a tourist attraction.