Raffles London at The OWO

For a century the Old War Office was one of the most closed buildings in Britain. Churchill worked here, Ian Fleming passed through the intelligence departments that inspired Bond, and the public never got past the door. After a long conversion it reopened as Raffles London, with 120 rooms and suites threaded through the Edwardian baroque interiors — marble staircases, oak panelling, and a few offices left recognisably as they were.

What earns it a place in a collection of retreats is the wellness floor. The Guerlain Spa is one of the largest in central London, occupying several levels below ground with a pool, thermal suite and a long treatment list, alongside Pillar Wellbeing for fitness and nutrition. It is entirely possible to spend a day here without going outside, which in Whitehall is a genuine luxury.

There are nine restaurants and bars, including a three-Michelin-starred room from Mauro Colagreco and a rooftop Japanese restaurant with views along Horse Guards. St James's Park is across the road, and Westminster, Trafalgar Square and the river are all within a few minutes' walk.