Iwi in Rotorua are angered by the chainsaw vandalism of a geothermal landmark in Waiotapu that had only just been restored.
The Waiotapu Hot and Cold Pools on the Waiotapu Loop Road are a highlight for locals and tourists.
But increased visitor numbers resulted in damage to the banks and vegetation, as well as significant littering.
The Ngati Tahu - Ngati Whaoa Runanga Trust and Department of Conservation put together a restoration plan carried out by 12 students last week clearing up rubbish and planted 100 native seedlings.
Police investigating believe whoever is responsible for the vandalism discovered last weekend used a chainsaw to cut through wooden railings, including a bridge railing.
Runanga trust environmental liaison officer Evelyn Forrest says what is of even greater concern is the hacking down of 10 prostrate kanuka trees, as they are nationally threatened with some at least 50 years old.