Buckingham Palace has announced plans to build a £2m memorial to the Queen Mother, four years after her death.
The Queen Mother died in 2002
Artists, architects and designers from around the world have been invited to submit designs, which will be judged by a panel and Prince Charles.
The winning design will be placed off The Mall, in London, near the statue of King George VI, the late Queen Mother's husband and the Queen's father.
The Queen Mother died on 30 March, 2002, at the age of 101.
Initial designs must be submitted by 31 January, and the memorial is due to be completed by summer 2007.
The project will be funded by the sale of a £5 coin marking the Queen's 80th birthday this year.
The brief for the memorial said that designers should take into account the foreign secretary's residence and Carlton House Terrace, which overlook the site.
It also mentions that materials should be sympathetic to those existing in the area, including Portland stone, granite, bronze and cast iron.
The brief discourages the use of water and "moving parts" so that it will be easy for the Royal Parks to maintain the site.
"Planting schemes should similarly be low maintenance in nature," the brief adds.
The Royal Parks also oversees maintenance of the Diana, Princess of Wales memorial fountain, a site initially plagued with drainage problems and slippery surfaces.