More than 250 people have attended a meeting to oppose a monorail and tunnel planned to be built on Department of Conservation land in Fiordland.
The monorail and tunnel in Milford Sound are intended to cut in half the 11 hour journey from Queenstown to Fiordland.
The Save Fiordland called the public meeting in Te Anau on Tuesday.
Daphne Taylor from the group says the projects would destroy kilometres of pristine beech forest.
Ms Taylor says that could threaten the area's UNESCO World Heritage status, which is a huge draw four tourists.
She says her group plans to form an incorporated society to fight the proposals.