Eastwoodhill Arboretum: Inside New Zealand's Noah's Ark ready for nuclear war

Tucked away in a valley just 30 minutes from Gisborne on the North Island is an extraordinary slice of New Zealand. If there was ever a nuclear holocaust, this place would be a glimmer of hope. It is essentially a Noah's Ark for trees.

Eastwoodhill Arboretum was the brainchild of Douglas Cook, who bought a scruffy piece of land 30 kilometres from Gisborne in 1910. During World War I, the budding botanist was injured and blinded in one eye – leading to a recovery in Britain. While there, he admired the beautiful country estates – surrounded by trees – and wanted to bring a slice of that back to New Zealand.

On his return, Cook started buying plants from the Northern Hemisphere and slowly built a population of exotic trees. One of the first things he did was plant a line of poplar trees along the main entrance to give it a grand English-like feel, which you can still see today. And, over the decades, his ambitious planting only gathered pace.

By the time of the Cold War, Cook became increasingly concerned about a nuclear holocaust and considered his property an insurance policy for the tree world. If a species was wiped out, his collection could be used to repopulate a rare species.

Today, the arboretum is a charitable trust, with more than 25,000 species of trees, shrubs, and climber plants. It's believed to hold the most extensive collection of Northern Hemisphere trees in the Southern Hemisphere. It is even home to 16 critically endangered species.

A visit to the 135-hectare property will have you feeling like you're in a Japanese forest one moment, then Central America the next. There is even a tree cathedral which is the exact dimensions of Westminster Abbey. You'll also find a floral spiral with a 750kg ball that floats on a constant flow of water.

There are six main walks to choose from, which can take 30 minutes to a full day for the true tree connoisseur. But the easiest way to get a grasp of the place, and an appreciation of rare trees, is to take a tour – which needs to be booked before you arrive. The experts who work and volunteer at the park, know every corner of it, and take guests around on the back of a jeep. It almost feels like Jurassic Park, except here, the dinosaurs have leaves.