London Open House weekend reveals hidden treasures

Open House London is an architectural festival that, for one weekend in September, opens doors to properties normally off limits to the general public. I've meant to take part for years, but always seemed to be out of town. This year, at last, the diary was free. With almost 700 possibilities, what to see?

After a bit of planning online, my No. 1 choice became obvious: Marlborough House. This was the magnificent townhouse of the Dukes of Marlborough, a project driven by the indomitable Sarah Churchill at the same time she was creating the family's country palace at Blenheim. She worked with Vanbrugh in the country, Christopher Wren in town, and the era's best artists and craftsmen at both houses. When the Churchill family gave up the London lease, the house returned to Royal ownership and became home to all sorts of minor royals and monarchs in waiting. It's now headquarters for the Commonwealth.

The blockbuster sight here is the main hall and the adjoining formal staircases. Classical paneling, tapestries, magnificent murals by Louis Laguerre, iron work by Tijou. All it's missing is a bit of Grinling Gibbons woodwork to make you think you were at Hampton Court or Chatsworth. Of course, it's the subject matter of the art that gives the creator away. Just as at Blenheim, all the wall decorations are bringing John Churchill's military victories to life. And I do mean glorious life. These interiors have clearly been recently restored and are well looked after. The magnificent ceiling started life at the Queen's House, Greenwich, and was moved here in a later re-decoration. I particularly enjoyed the allegory of rhetoric honing her sword on grammar's sharpening steel. Exactly the scene I'd give prominence to in my palace, if I had one.

You get to see a handful of other rooms, all gracious and spacious Georgian with nice plasterwork and big windows looking over expansive lawns. It's hard to believe you're in central London. The second most interesting room is clearly the commonwealth meeting room, in which a huge table features the chairs and flags of each member. It's quite a test of geographic knowledge, and certainly sparks some hunger for adventure travel. Tonga, anyone?

Next up was Horse Guards. Unlike Marlborough House, this turned out to be more impressive on the outside than in, but the guided tour by a succession of army officers was interesting. Perhaps it's because my first job was in the defence industry, but I've always had a soft spot for military people. In England, I note that they're some of the few who still find it acceptable to be proud of their glorious history. So, perhaps predictably, I thought the Irish Guard who explained the origin of his bearskin hat and let me stroke it, and the tremendously fit officer in camouflage who spun tales of the Duke of Wellington, just as impressive as the architecture. You actually only get to see two rooms here, the star sight being the office that once belonged to Wellington, still holds his desk and is the current office of the head of the army. Intriguing, but probably not worth the 40 minutes we waited.

The day's final visit turned out to be the most impressive. The Foreign Office headquarters building dates from the mid 19th century and was designed by George Gilbert Scott in the Italianate style. It is a bombastic, over-the-top building that beautifully expresses the confidence of empire. This, after all, was a temple built for the ruling of overseas possessions, and though its bones are of a Tuscan palazzo, its decor reminds you of nothing so much as an Austrian palace. Even the long corridors of offices are impressive, with their vaulted ceilings and mahogany doors.

But it's the vast public spaces, designed to impress, that still do. There's an internal courtyard, roofed over with glass, overlooked by loggias and encrusted with statues of imperial heroes. The board room off one of those loggia is a neo-Georgian gem from where they once made decisions about ruling India. The heroes of the original colonisation look down from noble portraits. (One of them of Lord Cornwallis. I only ever learned about him as the guy who lost the Revolutionary War and had to surrender to the Americans. Turned out he went on to become a successful governor of India and is commemorated all over this building.) There are the Locarno rooms, named after the treaty signed here, a suite of highly decorated painted interiors in the neo-Gothic style. You end with the most impressive, the towering State Staircase with its snowy expanses of marble and its gold gilt coffered ceiling. Around the tops are huge murals depicting allegories of Britannia. Here's Britannia Bellatrix, girding her boys for the wars they must fight to keep her safe. Followed by Britannia Pacifitrix, enjoying the rich harvests and leisure time of peace. And on from there.

It's no wonder that this place was falling to pieces by the '80s, with much of its glory shut behind plasterboard walls and dropped ceilings. Most Brits seem to be very squeamish about the imperial past and find patriotism to be tasteless and embarrassing; this building is the architectural embodiment of all that would make people with those sensitivities cringe. As an American, of course, I have no issue with either flag waving or with government buildings that glorify the nation.

I don't think either American or British history is blameless, nor do I believe their governments to be perfect. But I believe pride, patriotism and celebratory architecture can exist besides an ackowledgement of the darker sides of history. Fortunately, someone in the British government in the '80s felt this way, too, and kicked off a £100 million restoration process. I'm proud to think that at least a little of my early tax money went into this place. It's worth every penny.

So that's three down, 697 options still remaining. Plenty, I'd say, to get me excited about next year's Open House weekend.