With its shingle roofs and quirky turrets, its swaying rope bridges and aerial walkways that wind through the branches of 17 lime trees, the Alnwick Gardens Tree House, in Northumberland, looks as if it could have been dreamt up by the Brothers Grimm. But this project is more than just a fairytale.

At a cost of pound;3.3 million and more than a year in the making, the spectacular treehouse is a triumphant testimony to the versatility of wood: the living trees to which the 6,000sq ft structure is anchored; the immense open log fire in the restaurant; the thousands of hand-cut wooden tiles that make up the roofs; the gnarled and weathered chair backs reclaimed from old ox-carts. This enormous treehouse has been constructed from many timbers, including Canadian cedar, Scandinavian redwood, Siberian larch and English and Scots pine.

“We’re aiming to put the fun back into education,” says the project’s learning development manager Alison Hamer.

An extensive network of ramps and walkways offer extensive access for the disabled, too.

The main education room, known as the Roost, is suspended 60ft above the ground, supported entirely by the tree whose trunk soars up through the centre of the room. This arrangement means that the room sways with the natural movement of the tree.

The plasma screens that line the walls of the Roost allow the visiting pupils to watch specially designed education programmes. Computer-generated images take youngsters through the life of the tree in all its seasons, while puppet-style woodland creatures help to bring storytelling sessions to life. Benches are set around the walls, freeing up the floor space for activities.

But visiting pupils will not be restricted to the classroom, says Alison Hamer. The aim, she explains, is to get them out and about, exploring the stunning water features, the woodland walk and the labyrinth (due to be completed in March), where they can ponder the riddling stone inscription:

“Only dead fish swim with the stream.”

There are gardens galore at Alnwick, and by the spring these will also include the “poison garden”, which has been specially designed in consultation with a drugs awareness team to bring home to children and adults the dangers of drug abuse. Also under construction is a play park that has been designed to encourage children to take calculated risks in a “safely dangerous” play environment.

Cost of entry to the treehouse is pound;1.20 per child; pound;2 for a combined visit to the castle and gardens. A teachers’ pack is available.

For school group bookings telephone 01665 511350. For more information see: www.alnwickgarden.com