Towering at up to 300ft - or 36 storeys high - the coastal redwood is the skyscraper of the natural world. It is also one of the largest, rarest and most ancient species of tree in the world.

They are native to California, on the west coast of North America, and they languish, tragically, on the International Union for the Conservation of Nature’s endangered species' list.

They are so rare, in fact, concerned scientists are cloning them in labs to help save them from extinction.

But, incredibly, one of these magnificent trees - albeit not quite one of the giants just yet - grows in Allens Gardens, a little-known public park tucked behind Bethune Road in Stoke Newington. And no-one has any idea how it got there. 

“Where did it come from?” asks Sally Haywill, spokesperson for the Allens Gardens User Group. “We don’t know, but it is astonishing. It is currently the tallest tree in the gardens - looking like it is determined to live up to its reputation as the tallest tree in the world!”

It’s not the only surprise in Allens Gardens, a small nature-packed green lung and ecological haven in one of the borough’s most built-up areas.

“Amazingly, it is absolutely teeming with a wide range of trees, plants, fungi, insects and other wildlife, notably birds,” said Sally, 64, a long-time resident of nearby Cranwich Road. “We’ve identified 80 different plants, shrubs or trees growing in the gardens, including the quite rare wild service tree of Fontainebleau, which is apparently one of the best specimens in Hackney; and, of course, the coastal redwood.”

The gardens were created in 1874 by prominent Stoke Newington Quaker, Matthew Allen, who, according to historical records, built them as part of the overlooking “dwellings in flats for the middle classes”.

At that time, the communal green space included a croquet lawn, a long gravelled walk with flower borders, a lean-to greenhouse, gardener’s cottage, potting sheds, and coach house and stables. There was also a bowling green and a children's playground, and tenants could buy produce grown in the kitchen garden.

Then, for reasons unknown, the gardens were locked up and forgotten for nearly 100 years - until locals teamed up with Hackney Council, which manages them, to bring the wilderness back into community use in the early 1990s. 

Now people from all walks of life flock to the park, “valuing its serenity, seclusion and beauty”, according to Sally, a teacher, who added: “It gives us humans that live near it a wonderful, literal breathing space in a crowded city. It is a rare place of tranquility and refuge from a busy world." 

Indeed, the London Parks and Gardens Trust describe the gardens as having “the atmosphere of a secret garden”, shielded, as they are, behind homes on one side and bounded by the Enfield to Liverpool Street railway track on the other. 

In a nod to the park’s past life, Growing Communities, a community-led food-growing organisation in Hackney, set up one of its first urban market gardens in the park in 2004. It is now one of the project’s main growing sites, producing a vast array of salad leaves and organic fruit. The team also introduced a garden shed to the site as well as an eco-building with a compost toilet and living sedum roof.

However, the gardens, which sit in a designated nature conservation area, are not just an oasis for people: it is a much-needed sanctuary for insects and animals seeking succour and sustenance from the surrounding urban sprawl.

“The beautiful mature small leaved lime tree consistently flowers profusely each early summer, providing honeybees and other pollinators with a welcome source of nectar,” explained Sally. “The horse chestnuts flower in the spring, and provide vital early sources of both nectar and pollen. The dandelions at the top end are one of the very earliest sources of food for honeybees, and other insects, as are the flowers of the mirabellan plum tree in the woody area of the gardens.

“The ivy growing on trees and walls is the essential latest crop of flowers, around October, before the insects snuggle down for the winter.”

The little park forms part of a vital green corridor, stretching north-westerly up the long back gardens of Cranwich and Bethune roads towards the leafy banks of the East Bank and West Bank Nature Reserve, a 2000m stretch of railway cutting near Stamford Hill Station, as well as immediately southwards into Abney Park Cemetery.

Growing Communities is opening its eco-classroom and learning garden to the public on Sunday, 20 September, 10am-5pm, as part of Open House London and Urban Food Fortnight.

If you have an interest in the gardens or are just keen to find out a bit more about them, then visit the user group’s Facebook page. The user group held its summer fun day on Saturday, 5 September.

If you are interested in being informed of what's happening in Hackney's parks, sign up to the Council’s monthly newsletter by emailing:parks@hackney.gov.uk

The park is open every day.