Long, white, porticoed terraces on the north side of the square.
Eaton Square is a grand, rectangular,[a] residential garden square in London's Belgravia district. It is the largest square in London. It is one of the three squares built by the landowning Grosvenor family when they developed the main part of Belgravia in the 19th century that are named after places in Cheshire -- in this case Eaton Hall, the Grosvenor country house. It is larger but less grand than the central feature of the district, Belgrave Square, and both larger and grander than Chester Square. The first block was laid out by Thomas Cubitt from 1827. In 2016 it was named as the "Most Expensive Place to Buy Property in Britain", with a full terraced house costing on average 17 million pounds -- many of such town houses have been converted, within the same, protected structures, into upmarket apartments.
The six adjoining, tree-planted, central gardens of Eaton Square are Grade II listed on the Register of Historic Parks and Gardens. All of the buildings (Nos 1-7, 8-12A, 14-23, 24 and 24a to 48, 51-62, 63-66, Eaton House (No 66a), 67-71, 72, 73-82, 83-102 and 103-118) are statutorily listed, specifically at Grade II* save as to 1 to 7 and 63 to 66a which are in the mainstream, initial category of grade II. Nos 103 to 105 are leased and internally converted into the Belgian Embassy, as is No 106 for the Bolivian Embassy.
The houses in Eaton Square are large, predominantly three-bay-wide buildings, joined in regular terraces in a classical style, with four or five main storeys, plus attic and basement and a mews house behind. Most of the houses are faced with white stucco, but some are faced with underlying high-quality brickwork. Sides are set 350 feet (110 m) apart 1,615 feet (492 m) apart.
As to roads: the whole rectangle is divided into six compartments or zones as it is bisected lengthways by the Victoria or Buckingham Palace approach way to the King's Road which is very diversely and briefly successively named northeast of Sloane Square). Crossways it is spanned by four less important roads, all of which change name before during and after their transit across the square. All of the roads while in transit across the square assume the name Eaton Square and most of them are one-way, with no full outer circuit in any one direction permitted or possible.
In 1900, the Welsh Industrial Association held an exhibition at 83 Eaton Square, rented by the Winifred, Countess of Dundonald, the event was visited by Alexandra, Princess of Wales. The person presiding over the refreshment room exhibition was Kathleen, Duchess of Wellington, assisted by Mrs. A.J. Warden, with a party of attractive ladies wearing the national costume of Wales accompanied by Ivor and Albertina Herbert of Llanover's Harpist playing for the occasion.
Between 1916 and 1917, building 87 briefly became the 'Countess of Dundonald hospital', treating many of the wounded in the Great War, George V & Queen Consort Mary of Teck visited the patients at the Hospital, they were greeted by the Staff and Countess of Dundonald herself.
Co-fronting the north-east end is St Peter's, a 200-feet-long, tree-lined Church of England church, in a classical style, fronted by a six-columned Ionic portico behind which is a slender clock tower. It was designed by Henry Hakewill and built between 1824 and 1827 (during the square's building).
Between 1940 and 1944 the Belgian government in exile occupied its three numbers which have been long used as that country's embassy in Britain and further premises in central London as their lesser homes and offices.