Two Kiwi artists are close to the end of a 10-year labour of love building stunning sculptures around the planet. Wanaka-based Martin Hill and Philippa Jones are behind the Fine Line Project, which when completed, will have seen 12 temporary sculptures built on high points around the globe and linked by a symbolic line around the Earth.
The first in the series was at the summit of Mt Ngauruhoe in Tongariro National Park. The couple spent two nights camped on the crater in mid-winter to create a snow sculpture.
Since then, they have made others in the US, Madagascar, Canada, Scotland, Switzerland, Iceland, Kenya, the Arctic and Antarctica.
Each sculpture is made from materials gathered near the site and usually remain intact for only a few hours. Jones says the art works' limited life-span is a metaphor for sustainable design in nature.
"They return harmlessly to nature where they came from, to be a nutrient for new life," she says.
The only evidence of the sculptures' existence are photographs exhibited around the world.
Ever-changing variables in nature make the project unusually challenging.
"Conditions such as wind, tide, cloud, the angle of the sun all play a part."
Plans for the final two sculptures haven't been confirmed. The couple hope to get funding for a book, a film and more exhibitions.
Hill describes the most recent sculpture on Ross Sea Ice in Antarctica, right, as challenging and rewarding. "It's one of the most extreme environments on Earth and also one of the most fragile."
The Fine Line Project is a way of challenging the way in which man-made systems interrupt nature.
The pair have received international accolades for their work and this project is the latest ephemeral art-based project they have put together.
Others include Watershed, which was a year in the making.