Louis-Henri de Bourbon, the seventh Prince de Conde, is my favourite eccentric - a character straight out of Monty Python. Mention him in conversation and people will smile knowingly and slightly nervously, as if they fear being taken in.
Obsessed with horses, the Prince de Conde was convinced that he would be reincarnated as a horse, so, being used to life in a superb chateau, he built an enormous and luxurious stable block just across the road. It had 5m-thick walls, 2,000 windows and a hydraulic lift - one of the first ever and still in working order. Looking as magnificent as any emperor's palace the stable block now houses a horse museum, the Musee Vivant du Cheval. Imagine a building the size of Buckingham Palace with almost all the rooms filled with exhibits.
The Prince de Conde's family home at Chantilly (the place where he lived through his first existence!) has a perfect setting and is crammed with sumptuous furniture and paintings, something unusual for a French chateau. It fairly drips with masterpieces and you could fit my house into the library. Raphael's The Three Graces would have pride of place in any other chateau but at Chantilly it has to share a wall with a mass of other paintings by such as Watteau, Van Dyck and Delacroix.
The chateau is almost surrounded by lakes and ponds and has the most sublime grounds. When driving towards Chantilly from the A1 autoroute the chateau is glimpsed through a gap in a high wall and first-time usually visitors stop, pull in and walk back to check it is really that good. It has an almost fairy-tale look. You half expect to see musketeers suddenly burst across the gardens, biff the Cardinal's men, whistle up their horses and race off to Paris to save the Queen.
Visiting Royalty and state representatives are normally whisked off to sample the predictable delights of Versailles. When Richard Nixon, the US President, was taken to Chantilly, near the end of a state visit, he was surprised and gobsmacked, or whatever the American equivalent is, and he did wonder why his French hosts had bothered taking him to Versailles.
Chantilly has a style untouched by time's passing. With so many exhibits and so many stories to go with them, it is a great chateau crammed with centuries of history.
In the Twenties a couple of shopkeepers from Alsace got splendidly drunk at the Chantilly racetrack, stole some ladders and broke into the chateau. They stole a rather special pink diamond. Some years later a cleaning woman in a Paris hotel took a peach from a dish in one of the guest rooms. She bit into it and her teeth almost cracked on - the diamond! Yes, try telling that to an insurance company.
In one corridor a magnificent landscape of Paris in 1649 is barely recognisable, clumps of houses and buildings surrounded by tree-covered slopes. The only clue is the familiar outline of Notre Dame, looking much larger than now.
There are attractions in the grounds but all are discreet and in sympathy with the 18th-century ambience. You fully expect to turn a corner and see a bewigged string quartet playing Mozart. Small electric boats glide along the canal looking just like the craft in old paintings of the house. An air balloon floats up to 150m but remains secured to a steel cable.
The balloon is supremely safe and serene and has apparently cured many people of their fear of heights - myself included. Cyrille, our pilot, was one of the calmest human beings I have met.
The Musee Vivant du Cheval tells just about everything there is to know about the horse. It is as thorough as any special interest museum can be and is not just for pony-mad young people. There are special shows, but the daily equestrian displays are worth arranging a visit around. One of the riders led her horse past me on the way to the stables: it winked at me and I'm sure she called it Prince!
Have you ever seen a dressage display? Think it's a frivolous entertainment? It did once have a serious purpose. In the days of heavy metal knights their horses were trained to thrust their feet forward with those short, jabbing movements to protect the knight from foot soldiers, and the sideways movements were to knock soldiers over like a row of skittles.
There are enough rooms for even the most blase visitors to come away with a special memory. Mine was a room devoted to some thrilling drawings based on proverbs inspired by Arab horses: "Dieu prit du vent du sud une poignee et crea un cheval auquel il dit 'Je te nomme et te cree Arabe,'" and "Le Pie - fuyez le comme la peste, c'est le fr re de la vache".
Half a day for the chateau and a half for the horse museum should be the minimum, leaving very little time to dash into Chantilly to buy some souvenir lace.
The Musee Vivant du Cheval and the chateau have places to eat, cheap but definitely five-star quality, and there is an excellent cafe in the grounds. Chantilly cream on fresh strawberries, or a local fruit dish, is a delicious benchmark for any dessert you will eat.
Chantilly is signposted at the Senlis turn on the A1 and is 40km from Paris.
Chateau de Chantilly, Musee Conde, tel: 00 33 3 44 62 62 62; fax: 00 33 3 44 62 62 61
Musee Vivant du Cheval, tel: 00 33 3 44 57 40 40; fax: 00 33 3 44 57 29 92
* If you have asthma and hay fever sufferers, let the horse museum people know before-hand - the normal entrance is through some stables and the air is very dusty