A park ranger living on the door step of Christchurch's Bottle Lake Forest Park says a spate of fires in the area is the worst he's seen in three decades.
Emergency services, locals and council are on high alert after seven fires were deliberately lit in the area in just under a month.
The popular walking and biking spot north-east of the city is visited by a million people a year and now the public are being urged to be vigilant and help solve the mystery.
Eleisha Foon went there to find out more.
