If there is one patch of London that belongs, emotionally at least, to the United States, it is Grosvenor Square. On July 20th, it reopens after a £25 million (about $34 million) transformation into what its owners are calling a climate-resilient urban garden — the most significant redesign of the square in 300 years, and only the fourth in its history.
It is also, Grosvenor says, the largest private investment in public green space in the West End in a generation. And for once the numbers back the rhetoric up.
Why Americans should care about this particular square
Grosvenor Square has been nicknamed “Little America” for the best part of a century, and during the Second World War it was known only half-jokingly as Eisenhower Platz — General Eisenhower ran his wartime headquarters from No. 20. Long before that, in 1785, John Adams moved into No. 9 as the first American minister to the Court of St James’s, some years before he became the second President of the United States. The house is still there, with a plaque.
For most of living memory, the square’s west side was filled by the US Embassy — Eero Saarinen’s 1960 building with its gilded eagle — until the embassy decamped to Nine Elms in 2018 and the building began its own second life as a hotel. What remains, and what the redesign has deliberately protected, are the memorials: the statue of Franklin D. Roosevelt, the Eagle Squadrons memorial to the American volunteers who flew for the RAF before Pearl Harbor, and the 9/11 Memorial Garden, where Londoners left flowers in 2001.
The Roosevelt statue is worth pausing on. When FDR died in 1945, the money for it was raised by public subscription from the British people, with individual donations capped at five shillings so that it could not be bought by the wealthy few. The full amount came in within days. Eleanor Roosevelt unveiled it in 1948. It still stands at the heart of the square, and in the new design, the planting frames it rather than hides it.
What’s changed
The square was laid out in the 1720s by the Grosvenor family, who still own it — this is the estate behind the Duke of Westminster, and Mayfair is essentially their back garden. Fittingly, the redesign reinstates the original 1720s oval at the center, a piece of Georgian geometry brought back after centuries of accretion.
Around it, the change is dramatic. The square has gone from under 1% planted to nearly 50%, with 70,000 new plants across 63 species, 80,000 bulbs, 44 new trees, two new wetlands, and new woodland. The design is by architects Tonkin Liu, delivered with BDP.
The planting strategy came from Professor Nigel Dunnett of the University of Sheffield, one of the most influential horticultural figures of recent decades — the naturalistic, meadow-like style you may know from the London Olympic Park. Dunnett died in April 2026 at the age of 63, which makes Grosvenor Square one of the last major works to carry his signature. It is a rather moving legacy to leave in the middle of Mayfair.
The ‘climate-resilient’ bit is not just marketing
Underneath all this, some genuinely unglamorous engineering. The soil has been decompacted and restored across 15,000 square meters — after three centuries of feet, that matters more than it sounds — and the square can now soak up as much as 1.4 million liters of stormwater, taking pressure off London’s Victorian drains when the city gets the sort of downpour it increasingly gets. A garden square, in other words, doing a job as well as looking pretty.
There is also a long list of things visitors will actually notice: 300 additional seats, public toilets, drinking water fountains, better lighting and CCTV, clearer entrances, a new education center with programming by the London Wildlife Trust (funded by the Westminster Foundation), and a new café kiosk. More than 7,000 Londoners fed into the design, which is largely why so much of the list is about feeling welcome and safe rather than about horticulture.
“We challenged ourselves to consider not only what looks good, but also what the city actually needs.”
James Raynor, CEO of Grosvenor Property
The Duke of Westminster called the reopening “a very special moment for Grosvenor and for this part of London,” while the Mayor of London, Sadiq Khan, said he was “delighted to celebrate the reopening of Grosvenor Square following its transformation into a vibrant new green haven.”
For visiting Americans, it adds up to something neat: the square where John Adams lived, where Eisenhower planned a war, and where Britain paid five shillings a head to remember Roosevelt, is now also one of the greenest, wettest, most deliberately future-proofed corners of Mayfair. It is free, it is open, and it is a two-minute walk from Bond Street.
If You Go
- What: Grosvenor Square, reopened after a £25m (about $34 million) transformation into a climate-resilient urban garden
- Where: Grosvenor Square, Mayfair, London W1K
- Reopens: July 20, 2026
- Cost: Free — it’s a public garden square
- Look for: The Roosevelt Memorial, the Eagle Squadrons memorial and the 9/11 Memorial Garden, all retained
- Nearest station: Bond Street or Marble Arch
- More: grosvenor.com
All images: Stuart Bailey Photography / Grosvenor.
A Little Bit of London In Your Inbox Weekly. Sign-up for our free weekly London newsletter. Sent every Friday with the latest news from London!