Lake Vaihiria is a muddy-green crater lake surrounded by low trees and is more the destination than the highlight.

BBC: Five ways to experience Tahiti's waterfall valleys

Dr Bodenschatz and his team are now scrutinising video footage of the lava lake in the Kilauea crater in Hawaii, to see if its zig-zags are produced by the same pattern of cooling and plate-spreading that is observed in the wax.

ECONOMIST: Geophysics