It starts with a hiss and a roar, and ends with a jump in a lake.
Possibly the world's most unique marathon, the Tarawera Trail Marathon and 50km starts in the mists of Te Puia when nearly 1500 runners and walkers treat themselves to some of the world's most beautiful scenery while completing the challenge.
A range of run/walk challenges are scheduled, and numbers are up 500 from last year.
Event creator Paul Charteris puts the increase down to the addition of the Tikitapu Trail which is either a 16km or 23km event.
Many marathon participants' family and friends have entered the shorter distance event to give them something to do while they wait for the marathon to finish.
"The Tikitapu course finishes nearly half way along the marathon, so people are doing this and can take a boat ride to watch their family finish the marathon," he said.
Last year's participants described the event as "breathtaking", "fantastic" and "amazing" on Facebook, and applauded its organisation.
About 250 volunteers are needed to make the event a success and they come from a variety of community organisations who get a donation for helping.
However, Mr Charteris said the event had been "a victim of our own success" because many of its volunteers signed up to take part the year after, leaving them "wiped out" for the next year.
Once again participants will be farewelled at Te Puia by kapa haka group Mauri Oho, then it's full steam ahead through the Hemo Gorge, into the Whakarewarewa Forest and along vistas of farmland, Lake Rotokakahi, Rotomahana and Tarawera.
Mr Charteris believes this marathon is the most unique in the world, and 179 people from 24 countries are taking part this weekend to see for themselves.
What: Tarawera Trail Marathon and 50k Run/Walk
Where: Te Puia
When: Tomorrow 8am to 10pm