A spectacular 200m-long chasm discovered on a Rotorua farm could have spelled danger for farm workers early on Monday.
Tumunui South farm manager Colin Tremain said the "tomo" was 200m long, 30m wide and had a depth of 20m.
Tomo are formed when ground water dissolves underlying limestone rock. The dissolved hole enlarges to a point where it can't support the ground above it.
"It goes over half the race so if any of the workers had been going full speed along the race before it was discovered, they would have been in a bit of trouble," Tremain said.