If the Seven Wonders of the ancient world, only the Pyramids of Giza have survived through to the modern age. And whilst the Great Wall of China is supposedly the only man-made structure visible from the Moon, the Pyramids must surely be the most celebrated and recognisable group of monuments on this planet.

Many sightseers approach the Pyramids preparing to be underwhelmed; after all, such is our familiarity with the image, that the reality is bound to disappoint. Yet whether seen from afar or in close-up, they never fail to amaze.

One's first impression is incredulity at their sheer scale. Yet once the initial visual impact subsides (and believe me, this takes some time), there are other less tangible factors that continue to draw your interest. Their age, for example. And how on earth were they built? And why? Several centuries of academic research has revealed most of the truths about the Pyramids of Giza yet, tantilisingly, some of their secrets remain. For many visitors, this is part of the appeal.

The picture-postcard image of the Pyramids of Giza, carefully cultivated by Egypt's tourism industry, presents these monuments in a striking desert setting. It comes as some surprise, therefore, to find the Pyramids literally on the outskirts of Cairo itself - Giza being little more than a suburb that appears ready to succumb to the capital's relentless expansionist sprawl.

And though there are other pyramids in Egypt, often in more appealing isolated locations, those at Giza are the biggest and best - the "apogee of Pyramid-building". In practical terms this means that the Pyramids of Giza are both easily accessible as a short excursion from the centre of Cairo, and heavily visited. Whilst Egypt's present security problems mean that the Pyramids are currently less crowded by tour groups than usual, it does mean that the army of hustlers, touts, "guides", camel-owners and souvenir hawkers are even more persistent in their attempt to extract every last cent of the tourist dollar. On the other hand, if you want a souvenir glow-in-the-dark pyramid, or a Sphinx with "real" flashing eyes, then this is the place for you - just be prepared for some serious haggling.

The "Giza Group" comprises three main Pyramids, the instantly recognisable Sphinx, plus a number of smaller subsidiary buildings. All were built during the 4th Dynasty of the Old Kingdom, between 2589-2530 B.C.

The largest, the Pyramid of Cheops (or Great Pyramid), stands almost 140 metres high and covers an area of 5.24 hectares at its base (though when built it was several metres taller, having subsequently lost its granite capstone and most of the outer facing of Tura limestone). It is estimated that 2.3 million blocks of stone were used in its construction, each weighing on average 2.5 tonnes.

Those who have some difficulty comprehending such figures may prefer to consider the following analogies: you could fit Westminster Abbey, St Paul's Cathedral, St Peter's in Rome, plus the Cathedrals of Florence and Milan inside the space occupied by the Great Pyramid, and still have some room left over. Alternatively, Napoleon calculated that the three main pyramids at Giza contain enough stone to build a wall 3 metres high and 30 centimetres wide all the way around France.

The Great Pyramid is the funerary monument of Khufu (Greek: Cheops), who's status as absolute ruler is reflected in the grandiose nature of this tomb. Little is known about him, with many clues having been lost when the Pyramid was looted just centuries after its construction. In fact, the only reason we can still view his red granite sarcophagus is that it is 2.5 cm too wide to remove along the entrance passage (thus suggesting that it was placed in the chamber during the construction of the Pyramid).

There are three chambers to be explored inside the Great Pyramid and though the stonework in the "Great Gallery" is worthy of detailed examination, the main thrill of being inside comes from the sensation of standing within six million tonnes of stone blocks!

One of the Great Pyramid's last mysteries, the four meticulously crafted shafts that travel at precise angles from the "King's Chamber" and "Queen's Chamber", through the body of the pyramid to the outer walls, has been unravelled. Originally supposed to be for ventilation, computer-generated models now suggest that the shafts were aligned to various star constellations in ancient times.

Egyptologists believe that stars were viewed as heavenly counterparts to the land, inhabited by gods and souls of the departed. Thus these "star shafts" were used to direct the spirit of the dead pharaoh to the key stars. Their accuracy increases the awe in which we hold the architects and builders of these monuments.

A number of boat-shaped pits have been excavated around the Pyramid, one of which contained the dismantled remains of a 43m long wooden boat. It is suggested that this boat may have been used to transport the pharaoh's body at the time of the funeral, as well as providing a means of transport between the stars in his after-life.

The second pyramid, the Pyramid of Chephren (Khafre), is marginally smaller, though its position on somewhat higher ground gives the illusion that it is actually taller than the Great Pyramid. Built for Cheops' son, it is flanked by the well preserved Mortuary Temple of Khafre, which is in turn linked by a causeway to the Valley Temple (the latter of which is largely intact since it lay hidden in the sand for so long). Each pyramid here was linked to a funerary complex, intended to perpetuate the cult of the pharaoh for eternity.

The third of the group, the Pyramid of Menkaure (Mycerinus), would be impressive in its own right, though at "only" 66.5 metres high it is the baby of the group. Sadly, the fine sarcophagus of Menkaure, Chephren's son, was lost when the ship transporting it to England foundered off the coast of Spain.

And finally, the group is made up by the Sphinx: a work of art that is as enigmatic as the smile of the Mona Lisa. It's origins are unclear, though it is now assumed that it was hewn from remaining stone after the completion of the Great Pyramid. It is thought to date from the time of Chephren, however, since it is his likeness that the face is said to bear. It has been suggested that Chephren set it up as a sort of giant scarecrow to deter tomb robbers, though its unknown sculptor must have been aware that the soft sandstone would rapidly decay. In fact, had it not been buried in the sand for most of its existence, it would have probably disappeared by now.

Though standing 72m long and 20m high, this recumbent lion's body with a human head is dwarfed by the adjacent pyramids. After several failed (and damaging) false starts, the Sphinx's restoration programme is all but complete, though the original "beard" remains in London's British Museum (much to the chagrin of the Egyptians).

Somehow the Pyramids of Giza have managed to withstand the passage of the last 4,500 years, including the unparalleled attention of archaeologists and tourists this century. Yet even those who are generally immune to tourist brochure hype cannot fail to be impressed by this lasting testament to the ingenuity of man. When commercial space travel becomes viable, go to the moon to gaze down at the Great Wall of China. Until then, comeand marvel at the Pyramids of Giza.

Paris-based Dave Winter has travelled extensively throughout the Middle East, South and South-east Asia and Africa. He co-authored Footprint's Pakistan Handbook, wrote its Israel Handbooks and has had work published in a number of travel and airline magazines.

Published in Travel Africa Edition Three: Spring 1998. Text is subject to Worldwide Copyright (c)