The Spice Route was the sole channel of communication between isolated societies. The only windows these communities had on the world outside were their sea ports, and it was through them that such ancient societies transmitted and received information.

How is it that a predominantly Muslim country like Indonesia has a Hindu bird, the Garuda, as its national symbol? And why do macaroni, tagliatelli and spaghetti look and taste so much like noodles? It was questions like these that stimulated UNESCO to undertake this modern-day voyage.

Our ship left Venice to the sound of trumpets, escorted from the harbour by a flotilla of boats carrying Venetians in period costume.

We followed the itinerary of the ancient mariners - via Athens in Greece, Izmir in Turkey and Alexandria in Egypt - to the east coast of the Mediterranean.

Unlike Marco Polo's contemporaries, who had to make a hazardous overland journey from Alexandria to reach the Arabian Sea, we peacefully sailed through the Suez Canal and Red Sea to reach Oman, land of Sindbad the legendary Sailor.

Sindbad, whose adventures dominate the Tales of the Arabian Nights, is said to have been a merchant of Oman's east coast city of Sohar - which to the Arabs (like Venice to the Europeans) was known as the Gateway to China.

The lands described in Sindbad's stories recall the many countries to which traders from ports like Sohar and Muscat were sailing as far back as the eighth and ninth centuries.

On Oman's southern coast, we saw something unique to that country - groves of age-old frankincense trees.

It is from the sap of these craggy trees that crystals of fragrant incense are obtained - and it was frankincense (which at one time was as precious as gold) that attracted early traders here from far and wide.

In fact, the name of the now-ruined seaport of Samhram, the main exporting centre for Oman's frankincense trade, is found in many south Indian languages today as the word for incense - Samhrani.

Leaving Oman, the Fulk al Salamah sailed across the Arabian Sea towards India and Sri Lanka.

In addition to being regular ports of call for Arab traders who made use of the Monsoon winds, ports like Goa, Galle and Colombo became the earliest places of large-scale European settlement in Asia.

The Portuguese were the first Europeans to succeed in wresting control of the lucrative Spice trade from the Arabs.

Over the years they took away pepper from Calicut and cinnamon from Sri Lanka - but they left behind on the coast of these lands churches which are a pleasing marriage of European architecture and Indian art, Indians and Sri Lankans with Portuguese names like Perera, Fernando and Dias, and splicings of Portuguese words, like jannel for window and camisa for shirt, in the local languages.

They carried tomatoes and tobacco from Brazil to India, celery and rhubarb from Macau to Lisbon, and foods like dodol and blachchan from Malacca to Mozambique.

Traces of the musical rhythms brought by the Portuguese from Angola and the Algarve are still evident in Sri Lanka's traditional Baila songs.

Sri Lanka, at the virtual mid-point of the Spice Route, played a significant role in the spread of Buddhism. It was from here that as far back as 399 AD Chinese pilgrims like the monk Fa Xian carried the Buddhist scriptures back to their own countries.

And it was here that the Sinhalese kings (enriched, no doubt by the taxes collected from the trading ships making use of her famous harbour of Mantai) built the still surviving gigantic Buddhist stupas that rival in size and magnificence the pyramids of Egypt.

After Sri Lanka we sailed on to Melaka - today a steep town on the west coast of Malaysia but in the 15th century a prominent harbour where merchants of every creed and nation met, to barter their cargoes or await the arrival of a favourable wind.

How many of us today know that 400 years ago, no fewer than 84 languages were spoken in Melaka? In those days, the Indian, Arab, Persian and Chinese communities here each had their own district and played an important part in the life of the community.

Realising its strategic importance, as early as 1403 the Chinese Emperors began sending missions to Melaka and soon established diplomatic relations with the city.

One such Imperial envoy was Admiral Zheng He, who to further the Ming Emperors' policy of simultaneously maintaining prestige and promoting commerce, led several expeditions to the Southern Sea Nam Yeung.

Sailing on to China via the Spice Islands of Indonesia and the Philippines, we found constant reminders of the influence of the Middle Kingdom.

Every museum from Venice to Osaka contained exhibits which directly or indirectly, had been dispatched by the Chinese Empire to the then known world.

In fact, from Sri Lanka onwards, many of these ancient kingdoms had at one time or another paid tribute to China. One such was Brunei, a great exporter of camphor, on the north coast of Borneo; another was the Philippines, which profited from its strategic position and regularly attracted the Chinese merchant fleet.

All these great Spice Route ports must have been like modern-day Hong Kong, where trade has encouraged the meeting of different races and the intercourse of cultures.

Societies along the Spice Route now blend into one another, each unique in itself and yet sharing common bonds with the societies on either side.

Turkey, for example, has much in common with her Islamic neighbours to the east - and yet the influence of Greece on the west is ever present.

Further down the road Thailand obviously traces its roots to its giant northern neighbour China - and yet shares with Sri Lanka and Burma to the east the obvious influence of Theravada Buddhism.

Participating in UNESCO's voyage of dialogue was an experience from which all of us, including Chinese archaeologists, Australian historians, Senegalese sociologists, learned much, not only from what we saw, but also from what we heard from those with whom we travelled.

Lying on my bunk on the last night of our voyage just before we steamed into the Bay of Osaka, I could not help recalling Marco Polo's assertion when, on his deathbed, he was asked to retract the incredible stories that he had related of his travels.

He replied: ''I have not told half of what I saw.'' And neither, I must confess, have I.

All these great Spice Route ports must have been like modern-day Hong Kong, where trade has encouraged the meeting of different races and the intercourse of cultures. Great sail ships ploughing their way through the oceans opened up trade between Europe and Asia, and influenced the lifestyles of nations.