Some cash is going towards building the world's biggest tree house

The Duchess of Northumberland, wants to create the huge tree house - dubbed treetopia - as an adventure playground and education centre.

At more than 60 feet high, it will have rope bridges and slides as well as education and function rooms able to accommodate up to 300 people at a time.

It is part of the Alnwick Garden project, which already has the backing of the Prince of Wales.

The ambitious project is one of several in the north-east of England to receive grants totalling �2.3m from the Northern Rock Foundation.

The cash will go to support projects in Northumberland, County Durham, Teesside and Tyne and Wear.

Other donations include �500,000 for the Bowes Museum near Durham, �400,000 for Newcastle's Theatre Royal, �242,000 for the Hartlepool-based HMS Tincomolee and �236,000 for a youth project in Chester-le-Street.

The chair of the Northern Rock Foundation's Trustees, Richard Harbottle, said: "We are delighted to be supporting these exciting projects, which clearly show the talent and vision of cultural organisations in our region."

The Bowes Museum received a �500,000 grant

Lucy Wilkinson, spokeswoman for the Alnwick Garden, said the overall cost of the project was about �3.3m, of which half had already been secured from public sources including the European Regional Development Fund.

She said: "This is very good news because it is the first donation towards the project.

"Now the fund-raising will continue because we are hoping construction could start on site towards the end of September.

"We hope the project will be completed towards Easter next year although it depends on the weather."

In April the duchess handed control of the multi-million-pound garden over to a charitable trust.

The Northern Rock Foundation is an independent grant-making organisation formed in 1997, when the Northern Rock Building Society converted to a bank.

The Foundation's grants budget is now one of the largest in the country.

Its primary objective is to help improve the conditions of those most disadvantaged in society. It supports causes in Cumbria, Northumberland, Tyne and Wear, Durham and Teesside