Grosvenor Square, W1K, and evenings that start on the garden side

A quarter of an hour on the grass

The gardens are open to anyone and are at their best in the half hour before dusk, when the offices have emptied and the square belongs to residents walking dogs. There are memorials in it, including one to the American aircrew who flew with the RAF before their own country entered the war, and a garden planted for the dead of September 2001. It is a quiet place rather than a solemn one. One of our companions asks for the extra fifteen minutes before dinner specifically so that she can walk round it first.

The grand addresses on the four sides

W1K 2HP, on the south-eastern corner. W1K 6TF, a short walk east in Balderton Street, with its own small square in front. W1K 4HR, five minutes down Brook Street. W1K 2AL, six minutes south by Carlos Place. W1K 7TN, five minutes west on the lane.

There is no arrangement between this house and any of them, and there never has been. They are here as landmarks, so that you can measure the walk.

The working week in W1K

The square keeps office hours in a way the rest of Mayfair does not, and it shows in the bookings. Tuesday to Thursday are the busy nights, and the commonest request is a two hour evening at £500 beginning at half past seven, after a last call has run over. Friday empties early. Saturday is residents and hotel guests only, and is the easiest night of the week to book at short notice.

Stations and minutes

Bond Street is 4 minutes south-east, with the Central and Jubilee lines and the Elizabeth line, which puts Heathrow about half an hour away and Canary Wharf rather less. Marble Arch is 6 minutes north-west on the Central line. Green Park is 10 minutes south. Companions travel by car, and within the two central fare zones the journey is already inside the fee.

Who books around the square

People working long weeks in the offices on and behind it, who want an evening that does not require planning. Guests of the hotels on the four sides, often here for three or four nights and often booking twice. Residents of the flats along the northern side, which are quieter than anything else in W1. The request is nearly always the same: someone composed, on time, and able to carry a conversation that has nothing to do with the working day.

One Wednesday, as it went

A quarter past seven. A guest at W1K 2HP writes for three hours, starting as soon as possible. Tamsin suggests Tiffany, who likes a walk round the square before dinner and asks for the extra half hour to do it. Confirmed at twenty past.

Eight o'clock. They cross into the gardens while the light goes, then take a banquette on Upper Grosvenor Street at half past. She leaves at eleven. Three hours, £700, given to her at the door and not raised again by either of them.

Within ten minutes of the gardens

Roxi is twenty-three, black haired, gold at dinner and entirely uninterested in a crowd; she prefers to meet in a hotel lounge rather than a lobby and is comfortable at a few hours' notice. Tiffany wears something that catches the light and has a very quiet way of wearing it, and takes long banquette dinners over short calls.

Inside the same postcode, Angelika, Luna and Samanta walk over in minutes, Tina and Vanessa come up from Mount Street, and Jasmin and Nancy from the lane.

The square's neighbours

Mayfair surrounds it on three sides and begins at every corner. Mount Street is six minutes south past Carlos Place. Park Lane is five minutes west down Upper Grosvenor Street. North across Oxford Street lies Marylebone, about eight minutes on foot from the top corner. Bond Street and Marble Arch sit either side and are attended on the same terms.