Travel: The city of height

The observatory at the top of the Samaritaine department store hasn't changed since I was last there 20 years ago - or for that matter, since it was built in 1926. I clattered up a spiral staircase just wide enough for one person, into a glass and iron bubble like Captain Nemo's conning tower - and climbed out into a heady view of Paris. But this is the city's heart, not head; its arteries and organs radiate out from here as boulevards and grey mansard roofs shading distantly into purple.

La Samaritaine is an archipelagian department store, interlinked by bridges. Alongside, the roof of another Samaritaine building resembles a barge, all riveted lead and battened-down hatches. Beside it pours the petrol- blue Seine, bustling with bateaux mouches.

I remembered a circular ceramic panorama running all the way around the viewing platform, and it is still there, unchanged, disdaining to acknowledge upstarts like the Centre Pompidou, which protrudes like a binful of discarded computer parts a few blocks away. The painted panorama gives names to the spires and tree stumps that surround you - Montmartre, Pere Lachaise, Bois de Boulogne - as well as useful information such as the exact direction and distance of Moscow.

The secrets of the Parisian skyline have a fin de siecle charm, preserved by strict regulations on roof height. Up here, Jules Verne meets Tintin; it is not hard to imagine fleeing villians with mackintosh-clad heros in hot pursuit, clambering across a landscape of skylights, iron ladders and chimney pots.

Mind you, I used to live under one of those pretty mansard roofs - six flights up a urinous staircase - in a chambre de bonne, or "maid's room", under the Eiffel Tower. In summer the flat was so hot under its lead skin that on sunny days you got out by 10am or risked baking alive. The roof inclined at 45 degrees across the room, so that you could only stand up near the door. You did the washing-up kneeling by the sink in an attitude of prayer, or standing with your head sticking out of the sloping window. And the Tower loomed in the sky, a metal mantis.

The Eiffel Tower provides the highest view in Paris. I had not been up there for 20 years, either, and I remembered climbing to the top. Now, you are only allowed to climb to the "first floor", and to do that you have to queue for half an hour at just one of the tower's four corners, and no signs tell you which one it is and, when after trying the shut and shuttered Information Point you ask in the shops for help, haughty Frenchwomen wrapped in tatty foxfurs scream at you like caricature concierges from a Forties film.

But when you start to climb into that iron vortex - ah! Elegantly flung iron beams cartwheel around you, a Futurist painting come to life. How satisfying it is to work for the reward of seeing Paris fall away from you, how superior you feel to those whose need for instant gratification impelled them into the lift. Then you reach the first floor, and have to join them for a 30-minute scrum to get into the lift to the top.

Parisians tend to despise the Tower, scorning the notion of participating in an Italo-Japanese mob just to look at their own city. Gastronomes with large credit limits have an alternative: the Jules Verne restaurant on the first floor has a private lift.

But the view from the top is magical. It is not so much a bird's-eye view as a pilot's view from the gondola of an airship. For this chamber of iron plate and plate glass is the apotheosis of an epoch. A sequence of posters shows the Tower's involvement in everything from wireless telegraphy to air races, and there is an exhibition of magnificent ancient aero engines. You are enveloped by an age when technology was unambiguously for the moral and material Progress of Mankind.

The latest Parisian high is at the Institut du Monde Arabe. Its top-floor deck provides a restaurant and open-air cafe with fine views across the Seine to the south-eastern elevation of Notre Dame. The building represents a contemporary Gallic aesthetic; its southern facade Islamically eschews figurative decoration, and opts for a geometric pattern made from thousands of electrical motors sandwiched between plate glass. The entire wall is a living optic, its irises forever expanding and contracting to regulate the ingress of light, and so the inside temperature. Alas - according to an architect friend of mine - the cost of servicing all those little motors is beyond the limited budget of the Institut, and the eyes are frozen in mid-squint, gathering oily fur.

From the Institut, I crossed the Seine to climb the towers of Notre Dame. The gargoyle-framed views are marvellously evocative and here, high among medieval timbers, the guide invites you to do a Charles Laughton and bong one of Quasimodo's babies. "Jacqueline, Gabrielle, Thibauld, Marie!" The bells, the bells!

The weekend's penultimate Parisian high was Montmartre's Basilica of the Sacred Heart. I vividly recalled my last visit here: the newly installed Pope John Paul, engaged in his phenomenal world rock tour, visited Paris to uplift the masses in Montmartre. And I - no Catholic, but seduced by his pop-star appeal - clawed my way to the front of the crowd. In our thousands we basked in his charisma, and exhortatory platitudes rang out across the night-time roofs of Paris.

Now, it was twinkling night-time again, and too late to climb up into that oddly elongated cupola.

The Parachou restaurant provided a fittingly climactic view across the city, so seductive that time flew and suddenly I was late for the Eurostar.

I ran down through empty, curving cobbled streets until I managed to hail a cab in seedy Pigalle ( I once lived here, too, in a street of satin- frocked transvestite prostitutes). Most taxi drivers love to be asked to drive like hell. As the car screeched around comers and drove the wrong way down one-way streets, I experienced the weekend's last, and most adrenal high.

The Dorling Kindersley Paris guide is good on views. `Park Mode d'Emploi/ Users Guide', free from the Office de Tourisme de Paris, is also informative