They used to refer to them as the seven hills of Rome. Now there are eight. That is what they call it: lottavo colle or the eighth hill. Ascent and descent take 15-20 stupendous minutes, and it is best scaled in the morning when there is usually less of a breeze.

The hill can be observed intermittently in Villa Borghese, and is reachable with a four-minute walk from Porta Pinciana at the top of Via Veneto. It is, the publicity asserts, the biggest of its kind in the world the biggest tethered balloon that is, both in terms of size and the number of passengers it can whip aloft, a maximum of 30.

Today, it is the most popular hill in Rome, with small crowds of people queuing at the ticket office from 09.30 to sunset, especially on a fine day. After paying 14 (full fare) they are filtered into a boarding area, and escorted by pony-tailed Paolo Vanadia from Bologna, not to an old-fashioned hanging basket, but to a so-called gondola. This is a circular platform shaped like a ciambella a breakfast doughnut with a hole in the middle suspended by a myriad of cables from the enormous blue balloon, which is adorned with golden lion heads linked by festoons of garlands.

Waiting to board were 12-year-old Valerio and his grandmother, Lia Giorgi, and Valerio pronounced himself most excited at the idea of seeing Rome from a completely new angle. Also waiting were 29-year-old Massimo Cuello from Santiago, Cuba, with his Italian girlfriend, Anna Esposito, a doctor. Were here because we see the balloon every day from our bedroom window, she explained. The panorama from up there must be fantastic, he added.

It is standing room only on the doughnut and the pilot, as he is designated, warns through a loudspeaker: Please hold on tightly and maintain your present positions during take-off. Then, with a sudden jolt, the great craft soars 150 metres up into the sky.

Look! Theres the sea! And there are the Roman walls! exclaimed Nicky Killengray from Milton Keynes, England, clapping her hands. I never realised Rome was so big, and it looks so strangely flat instead of being all ups and downs. What she most appreciated were the colours: All the greenery, the red from the terracotta buildings against the white marble of the monuments. Other passengers were pointing to the Alban Hills and the Vittoriano, though they found the most easily recognisable landmark was the great dome of the Pantheon.

Michele Capano, the pilot at the control panel and in charge of the snaking hawser holding the craft to the ground, commented: Initially, people react with stupor and are a bit afraid. Then they calm down and begin to identify places they see every day, though from this height its not easy.

The holder of a regular pilots licence, as required by Italian law, Capano went on: Nobody has felt ill up to now, but if anybody asks, we return to earth at once. He then explained: The stiffer the breeze becomes, the more we have to reduce the number of passengers to avoid the pendulum effect, with the gondola swinging back and forth. The maximum we can stand is a wind speed of about 25 knots.

The balloon itself is stuffed with 5,500 cubic metres of helium gas, with each cubic metre capable of lifting one kilogram. The balloon is a very European affair: the maker is Aerophile S.A. of the whipped cream town of Chantilly near Paris, the sphere itself is produced in Germany and the electric winch equipment is an Italian job.

Patrizia Martelli from Verona, the superintendent on the ground, said: Once youve been up two or three times, you can pick out every obelisk in Rome, and there are a lot of them! Its worth going up both in the morning and afternoon, because the light is so different and you see two different Romes. As you see, everybody confirms in the visitors book what a stupendous experience it is. In the morning, school children come here and can be taught the principles of flight and lift, or are taken to walk among the clouds with their teachers for lessons on the history of Rome or its artistic treasures from a slightly novel standpoint.

In Italian, the word for balloon is mongolfiera after Montgolfier, the surname of two French brothers who in 1782 launched a balloon made of linen and paper. The air inside was heated by a fire on the ground, and its passengers were a befuddled group of animals. The first human ascent followed a year later, the balloon this time fashioned by a French aristocrat, the Marquis dArlandes, and a physicist, Pilatre de Roziere.

The superintendent of Romes balloon said: The flights end in December, but we do hope the authorities will issue us with a permanent permit.

If they do, then Rome really will have come into an extra hill.

Aerostato Arophile 5500 observation balloon, Viale del Galoppatoio, Villa Borghese. Open daily 09.30 to sunset. Tickets: 14 ordinary fare; 10 for senior citizens and 13- to 17-year-olds; 3 for children up to the age of five; 20 for flight plus airborne cocktail (prosecco) ordered in advance. Facilities for disabled. Flights are liable to cancellation in rain or bad weather. For information tel. 0632111511.

Picture: The popular eighth hill of Rome ascending over Porta Pinciana from Villa Borghese.