The world's best classic Citroëns Roughly the size of four football pitches, it is home to row upon row of almost every type of vehicle ever to carry the Citroën badge. About 500 examples, in all. There are rows of gorgeous, gleaming DS models, of course, including the world's oldest. Even at a glance that beautiful silhouette, characterised by the sloping nose, ground-hugging stance and dart-like tail lights, is unmistakable. There are entire squadrons of 2CVs including the yellow one, complete with fake bullet holes, that 007 drove in For Your Eyes Only and two venerable, not to say ragged, concept versions built in 1939. Along with a third, since restored, they were found walled up in the attic of a farm building at the Citroën test centre in the Nineties, having been forgotten after they were hidden from the Nazis. Covered in grime and very much in original condition, that is the way they will stay. Lest we forget, Citroën has a formidable rallying pedigree. This DS was raced by the inaugural World Rally Champion Bjorn Waldegaard Photo: JAMES LIPMAN In stark contrast there are legions of stately, shiny Traction Avants and a number of Type A Torpedo models, the firm's first mass-produced car. Possibly the most imposing cars of all are the towering, immaculately preserved Rosalies from the Thirties. This Aladdin's cave, not normally open to the public, is also home to a two-seater Citroën helicopter from 1971, a number of quirky H-type vans, a couple of Citroën tractors, two fire engines, a brace of half-track vehicles and a racy 1967 prototype Panhard 24CT. Most impressive of all, however, is the presidential section, and not just because it houses the DS5 Hybrid 4 that carried newly elected President François Hollande along the rain-soaked Champs-Élysées in May. Citroën has three examples of prototype 2CVs. They remain as they were found after being hidden from the Nazis and discovered in the 1990s Photo: JAMES LIPMAN What really stops you in your tracks is the 1968 DS21 Presidential. Looking like an Austin Powers film prop, it is 21ft long, 7ft wide and more than 5ft tall. The deep, squashy seats have been graced by two presidents, Valéry Giscard d'Estaing and Georges Pompidou. With its walnut veneer, chrome, acres of glass, deep carpets and cocktail cabinet, it's Versailles on wheels. The French do like their style. Tours of the Conservatoire are available only by request. More at citroen.co.uk/about-us/history/citroen-conservatoire