‘Wherever Raffles opens a hotel, it aims for it to be the best property in that location,’ concierge Emile at Raffles London at The OWO tells me.

My conclusion after spending a night in ‘The Old War Office’? They may well have succeeded in the UK capital.

This vast dazzling 120-room property, which opened as a Raffles hotel in September 2023, is stuffed to the gills with thrilling history, the service is faultless and, as my video footage shows, guests are ensconced in grandeur and exquisite luxury, in a post-card perfect location – opposite Horse Guards Parade and the official entrance to Buckingham Palace.

The trapezium-shaped building was constructed in Edwardian Baroque style and opened in 1906 as the War Office.

It was the centre of the British Army’s administration until 1964, containing 1,100 rooms; 2.5 miles of corridors; 22 lifts; 25million bricks; 26,000 tonnes of Portland stone; 50 acres of plastering; 19,000 feet of ornamental cast iron grilles installed around hallways and corridors to contain telephone and bell wires; and 18,000 square yards of Roman cube mosaic and terrazzo flooring.

MailOnline Travel’s Ted Thornhill checked in to Raffles London at The OWO, opposite Horse Guards Parade. Above – the staircase that helps make the lobby one of the most impressive in the world

‘Visit the pool,’ writes Ted, ‘and you’ll probably end up spending as much time taking pictures of it as you will swimming’

The building was where MI5 and MI6 were conceived and, while it didn’t serve as their headquarters, it was a day-to-day workplace for spies, including James Bond author Ian Fleming, a liaison with the Secret Intelligence Services during WWII.

This was where the chief of the imperial general staff, Alan Brooke, helped Sir Winston Churchill mastermind the Allied victory over Hitler.

During a fascinating hotel tour with Emile I learned more about the property’s absorbing past – and got a sneak peek inside some of its most prestigious suites.

Including arguably the top room – the Haldane Suite. Price for the night? Between £25,000 ($31,000) and £27,000 ($34,000), I’m told.

And what do you get for that? Something breathtaking.

The suite is named after Sir Richard Burdon Haldane (30 July 1856 – August 1928), who served as Minister for War between 1905 and 1912 and who helped establish the Royal Flying Corps, MI5 and MI6.

The space was used by him and subsequent government figures of distinguished significance.

The ever-affable Emile explained that four ex-prime ministers – David Lloyd George, H H Asquith, Winston Churchill and Anthony Eden – would have occupied the room, along with Herbert Horatio Kitchener (who devised the ‘Your Country Needs You’ campaign) and John Profumo, who was at the centre of the first modern sex scandal in 1963.

The Haldane Suite, which costs between £25,000 and £27,000 per night. Four ex-prime ministers – David Lloyd George, H H Asquith, Winston Churchill and Anthony Eden – would have occupied the room. Along with Herbert Horatio Kitchener (who devised the ‘Your Country Needs You’ campaign) and John Profumo, who was at the centre of the first modern sex scandal in 1963

The Haldane Suite is named after Sir Richard Burdon Haldane, who served as Minister for War between 1905 and 1912 and who helped establish the Royal Flying Corps, MI5 and MI6

He clandestinely used the office’s private elevator to bring in his mistress, 19-year-old model Christine Keeler.

The room now comprises two opulent bedrooms either side of a magnificent, stately living room, with furniture befitting an Edwardian palace, decorative 12.5-metre (41ft) -high ceilings, oak panelling and grand windows overlooking Whitehall.

The private elevator was removed, though.

I was also shown inside the Granville Suite, named after Winston Churchill’s favourite spy, Christine Granville. It costs around £17,000 ($21,500) per night and features an ensuite worthy of a Hollywood movie, with showers and toilets housed behind opaque screens in pillared ‘cubicles’ and a jewel of a standalone tub at the far end.

Emile guided us down into one of the two original basement levels where a telephone exchange was installed capable of operating in the event of a nuclear attack – and along the way pointed out the original cast-iron grilles and flooring in the corridors.

The Granville Suite, named after Winston Churchill’s favourite spy, Christine Granville

The Granville Suite features an ensuite worthy of a Hollywood movie, with showers and toilets housed behind opaque screens in pillared ‘cubicles’ (left). The suite costs around £17,000 per night

We finished back where we started, at the hotel’s jaw-droppingly grand marble staircase.

Winston Churchill’s staff used to line it to give him daily briefings, with the statesman positioned at the top outside what is now the Haldane Suite.

Today the staircase helps make the Raffles London lobby one of the most impressive in the world, by anyone’s standards, its Instagram-baiting allure boosted by a Murano-glass chandelier commissioned by the hotel.

Mind you, Instagram-baiting allure awaits around every corner.

Visit the pool, which occupies a space within the extra three basement levels Raffles dug, and you’ll probably end up spending as much time taking pictures of it as you will swimming. It’s magnificent.

The building was the centre of the British Army’s administration until 1964, containing 1,100 rooms

Saison, the former WO military library that’s now a lavish restaurant helmed by Argentine-Italian chef Mauro Colagreco. Breakfast, lunch and dinner can be enjoyed here

Our ‘ministerial suite’ bedroom, with its hushed opulence, is easy on the eye, too.

It has a marble bathroom of not just my dreams, but everyone else’s, and views of the Household Cavalry standing to attention opposite.

We dined in the evening and for breakfast in Saison, the former WO military library with a glass ceiling that’s now a lavish restaurant of notable calibre helmed by Argentine-Italian food wizard Mauro Colagreco.

At dinner, the pumpkin ravioli was ravishing, the wines by the glass gorgeous and the service delivered with military precision.

Pictured above is the The Guards Bar, which is located on the ground floor of the hotel

The Instagram-baiting allure of the lobby, writes Ted, is boosted by a Murano-glass chandelier commissioned by the hotel. The property has five basement levels, three of which were dug by Raffles

The standards remained impressively high in the morning, with an attentive and bubbly breakfast team delivering ‘the best eggs benedict’ my partner had ever tasted, porridge with almond flakes that would satisfy any native of Scotland and top-notch pastries.

The coffee also comes highly recommended, with Louis Roeder Champagne an option for anyone looking to get the party started early doors.

We left our bags in storage at the hotel while we met the Household Calvary horses opposite and explored the National Portrait Gallery, a few minutes by foot to the north.

Prince William had visited the hotel (above) for a charity event the week before Ted’s stay

The property’s basement used to house a telephone exchange capable of operating in the event of a nuclear attack. Now a Guerlain spa (above), helps to form the hotel’s subterranean guest-experience offering

When we returned every member of staff we passed in the lobby greeted us with a cheery ‘welcome back’.

Prince William had visited the hotel for a charity event the week before our stay.

He would have received the royal treatment, of course – but every guest is royalty at Raffles London at The OWO.

What a place.

In the battle of the capital’s hotels, this former hive of military activity has launched a devastating salvo.