One of London’s most celebrated green landmarks reopened its gates this summer following the most significant private investment in West End green space in a generation. Grosvenor Square, the second-largest public square in the capital, has undergone a £25 million redesign to adapt its 300 year old landscape for the reality of 21st century climate challenges. 

Marking only the fourth major redesign in its three century history, the decade long project transformed the historically minimalist lawn into a rich, biodiverse urban garden capable of absorbing up to 1.4 million litres of stormwater during heavy rain.

From lawn to living ecosystem

Historically, planting covered less than one per cent of Grosvenor Square’s footprint. Following its redevelopment, green coverage now spans close to half the square. The site features 70,000 new plants across 63 species, 80,000 bulbs, 44 new trees, and two newly introduced wetland habitats.

“When we approached the redesign of Grosvenor Square, we challenged ourselves to consider not only what looks good, but also what the city actually needs. The result is a public garden where climate resilience, biodiversity and access are built into every part of the design.” — James Raynor, Chief Executive of Grosvenor Property

Grosvenor Square Gardens, London. Photo: Stuart Bailey

To support this dense new flora, 15,000 square metres of soil, an area equivalent to two football pitches, was de-compacted and ecologically restored. In the weeks leading up to its official opening in July, wildlife had already begun returning to the Mayfair square, with sightings of ducks, butterflies, and dragonflies along the new woodland paths.

Honouring the square’s heritage

The design, originated by London architecture practice Tonkin Liu and delivered by BDP, balances ecological functionality with a respect for Mayfair’s historic urban fabric. The site’s original 1720s oval footprint has been reinstated at the centre of the layout, cleanly integrating the square’s existing historic monuments, including memorials to Franklin D. Roosevelt, the Eagle Squadrons, and the victims of 9/11.

Grosvenor Square Gardens, London. Photo: Stuart Bailey

The master planting strategy was led by Professor Nigel Dunnett of the University of Sheffield, one of Britain’s most influential figures in ecological urban horticulture. Following Professor Dunnett’s passing in April 2026, the completed square stands as one of his final legacy projects, embodying his lifelong work in integrating natural habitats within urban settings.

Access and education

Shaped by consultation feedback from over 7,000 Londoners, the updated square incorporates practical infrastructure to support year-round community use:

Grosvenor Square Gardens, London. Photo: Stuart Bailey

  • 300 additional seats along seasonal garden borders and woodland paths.
  • Enhanced accessibility, improved entryways, public toilets, water fountains, and night-time lighting.
  • A dedicated education centre with nature programming delivered by London Wildlife Trust and funded by The Westminster Foundation, and a new café.

“The Square has been at the heart of Mayfair for three hundred years, and our responsibility has been to respect that history while ensuring it is ready to serve London for the next century. This transformation is about showing how historic urban spaces can work well for people, nature and the climate.” — The Duke of Westminster

A model for central London’s historic squares

The project arrives at a time of broader regeneration across Mayfair and the West End, serving as a blueprint for how historic, protected green spaces across London can address urban heat island effects, biodiversity loss, and flash flooding, without losing their cultural identity.

Commenting on the reopening, Mayor of London Sadiq Khan noted: “This extraordinary urban garden showcases how investment in our public spaces can help to build a greener, fairer and better city for everyone.”

Grosvenor Square is now open daily to the public, offering residents, workers, and visitors a place to connect with nature in the heart of central London.

London Parks & Gardens Inventory provides public access to a wealth of information on over 2,500 parks, gardens, squares, churchyards, cemeteries and other sites of historic interest across the whole of London. Learn more about the Inventory and how we work with our amazing volunteers to assemble this information and the history of its creation.