LONDON (Reuters) -A memorial to honour Queen Elizabeth in London's St James's Park will feature a statue of Britain's longest-reigning monarch on horseback, another of her arm-in-arm with her husband Prince Philip and a glass bridge, the project committee said.

Elizabeth II died at her Scottish castle on September 8, 2022, after more than seven decades on the throne. She was 96. Her death provoked days of mourning and tributes from across the country and the world.

St James's Park, which is located opposite Buckingham Palace, was chosen as the best site to pay tribute to her reign, and under the plan announced on Tuesday the park will be reshaped, with two new areas of gardens and two new gates.

The committee chose the plans drawn up by Foster + Partners, a firm headed by Norman Foster, one of Britain's most influential architects, who is known for the Gherkin building in London's financial district and the Reichstag dome in Berlin.

Foster, 90, knew Elizabeth personally after she appointed him to the Order of Merit for services to architecture in 1997, and he said his idea was to use the site to narrate her legacy and the extraordinary story of her life.

The new glass bridge is inspired by the tiara she wore at her wedding while the two gates and two gardens reflect the way Elizabeth balanced tradition and modernity, public duty and private faith, and Britain and the Commonwealth, Foster said.

"It's really creating something which is timeless, and reaches across all ages and interests and conveys the values of Her Majesty, which were a mixture of the formal and...delightful informality," he told BBC Radio.

The design will be finalised by April 2026 and the memorial could be completed one to two years after that, Foster said.

(Reporting by Sarah Young; editing William Schomberg)