The Parks Trust, formerly known as Milton Keynes Parks Trust, was established by the Milton Keynes Development Corporation to own and manage, in perpetuity, the strategic open space in Milton Keynes. It took a 999 year lease of 4,500 acres and at the same time was given an endowment of around £20m. The endowment was mainly in the form of commercial property in Milton Keynes and the rental income is used to fund the Trust. The Trust’s green estate now comprises around 6,000 acres of parks, meadows, river valleys, woodlands, lakes and the landscaped corridors which run along the main grid roads– about 25 percent of the new city area. As the city has continued to grow, new parks and open spaces are being established and transferred to the Trust with an endowment. The endowment sum that is required is the capital sum that we need to invest to generate the annual income to cover the maintenance costs each year in perpetuity.