The journey across Asia must still be considered the most venerable of all overland routes. History provides us with sketchy accounts of the great overland journeys of Alexander, Hannibal and Marco Polo. Further afield, ancient stories of Ghengis Khan and more latterly of the explorers along the Silk Route still provide inspiration to travellers to explore the further reaches of Asia. Overland journeys to India and beyond are still practicable, despite international conflicts such as the 1991 Gulf War and continuing tribal warfare in Afghanistan. The Middle East continues to present some instability, yet there has always been a safe and viable alternative route to follow. Now that the revolution in Iran is some 20 years in the past, the country is no longer the bureaucratic and logistical nightmare that it was during those few years of turmoil. Visas are available to all, even holders of US passports, and even five-day Transit Visas can be extended to up to 14 days with relative ease within Iran. But in the wake of the Gulf War, and despite promises to the Kurdish people by the West, there is still unrest in south-east Turkey (Turkish Kurdistan). As the suppressed and isolated Kurds struggle once again for autonomy, the Turkish government's answer - as ever - is to send in the army. This is definitely a region to be avoided, but fortunately (for travellers) there are alternatives. With the continuing effects of the break-up of former Yugoslavia, the most direct route to Istanbul via Zagreb (Belgrade following the E5) is still not recommended. A diversion through Hungary, Romania and Bulgaria can nevertheless bring you into Turkey (and Asia) without covering too many more kilometres. It also provides a glimpse of countries that have experienced considerable change since the break-up of the Eastern Bloc. Alternatively, you can travel via Italy, taking a ferry to Greece from Brindisi and continuing via Thessaloniki.

The crossing of Asia remains a bureaucratic challenge, however, so go prepared with the necessary vehicle documentation, and most importantly a Carnet de Passage and vehicle registration document, both correct in every detail as border officials can be very uncompromising. In addition you must have minimum third party insurance. Most international insurance companies will cover you with a 'Green Card' at least as far as Turkey and possibly Iran, but afterwards you will be purchasing locally as you go. Furthermore, virtually all nationalities now require a visa for all countries east of Turkey. These must be obtained before departure, as they cannot be issued on entry and are often not obtainable in neighbouring countries.

Istanbul and all routes east

Istanbul, where Europe meets Asia, is the perfect place to pause in order to finalise your plans and timings. The city is well serviced, and although it is not the Turkish capital most countries on your route have diplomatic representation here. It also makes an ideal meeting point for travellers heading east, and you may be fortunate to meet some who are returning westbound: recent experience is always the most reliable source of current information.

The most direct route to Iran and beyond is via Ankara (the capital), then up to the Anatolian Plateau through Sivas, Erzincan, Erzurum to Dogubayazit (last stop in Turkey). This region has been affected sporadically by Kurdish unrest, so check with the local authorities before leaving Ankara. Never travel at night and stay in towns rather than camping out.

The alternative route, longer and more rewarding by far, heads south from Istanbul via the Gallipoli Peninsula, crossing the Dardanelles to Canakkale. After that the choice is yours, but why not visit Troy, Bergama, Kusadasi (and Ephesus), then go east to Pamukkale before crossing the mountains to the south coast? You could spend a few days lazing around the beaches and coves of Olu Deniz, before following the dramatic coastal route from Fethiye via Kas to Antalya, Side and Anamur. This route is not only scenically spectacular but also dotted with ancient Roman sites, Crusader castles and typically Turkish coastal villages.

Once you have travelled virtually the entire length of the south coast, you reach Adana, which lies at a crossroads: south to Syria and a diversion to the Middle East (see below) or north across the Taurus Mountains to Cappadocia (and the environs of Goreme) and on to rejoin the main E5 route at Sivas.

Diverting into the Middle East

If time and money permit, you should certainly consider visiting Syria, the Lebanon and Jordan. More recent conflicts and friction between neighbours restrict travel possibilities, but the situation is constantly changing. At time of going to press, the Israel/Palestine peace process could well change the entire area - even Syria and Israel are at last talking to each other over conference tables.

Visas are required for both Syria and Jordan and should be obtained before you leave Europe. You do not require any other special paperwork for your vehicle, but be patient with Syrian border procedures, which can be very autocratic and time- consuming. Lebanese visas may be obtained either in Damascus or on the border.

From Adana, head south to the coastal town of Iskenderun, cross into Syria at the Baba el Hawa border and carry on to Aleppo, which has both the largest medieval citadel in the world and the largest bazaar/souk in the Middle East. Further south you come to the waterwheels of Hama, then on to Homs and Damascus, Syria's bustling capital. A visit to Lebanon can be arranged from here. Cross the Jordanian border at Dar'a, then carry on to Amman, the capital. The city offers little of interest, but the ancient site of Jerash to the north is well worth a visit.

Jordan holds surprises for many travellers. Not only are the people extremely friendly and hospitable (65 per cent of the population being Palestinian), but the country is also geographically stunning and historically dramatic. A route via the Dead Sea takes you along the King's Highway from Madaba to Kerak and Petra, the hidden city of Nabateans. Several days here would not be wasted, before heading south to the Aqaba on the Red Sea.

You can complete a circuit by returning to Amman along the Desert Highway, with a highly recommended excursion en route to Wadi Rum (famous in the days of Lawrence of Arabia). Take a local Bedouin guide and you will travel through some of the most spectacular desert scenery to be seen in the Middle East.

From Amman it is possible to take an excursion to the 'West Bank' of the Jordan River, namely Israel, but you require a special permit (obtainable in Amman) and you are not permitted to take your own vehicle. Fortunately, border controls between Jordan and Israel do not stamp your passport. On returning from Jordan, however, you must ensure that you have no evidence of Israeli goods, souvenirs etc., or you will run into great difficulty when you attempt to re-enter Syria and afterwards Iran.

At the time of writing, there is still no recommended route into Iraq. Furthermore, travelling overland through Saudi Arabia is still prohibited, though (if you were considering shipping to the Gulf States or beyond) transit permits are occasionally issued for travel from Jordan to coastal parts.

On re-entering Syria from Jordan and returning to Damascus, consider heading north- east to the remote desert ruins of Palmyra - the Roman city built on an ancient Greek site dating back to 1000 BC. Your route could then take you to Lake Assad on the Euphrates, returning via Aleppo to re- enter Turkey. Owing to the present Kurdish unrest, the regions to the east and north-east of Gaziantep and Diyarbakir are best avoided, and certainly any route around Lake Van is usually considered out of bounds.

Iran to India

The only practical point of entry into Iran from Turkey is the border of Barzagan. Before entering, in order to conform with Islamic dress codes women must equip themselves with a chadoor, a long loose-fitting gown covering head and shoulders and concealing the outlines of the body. This must always be worn in public. Alcohol is strictly forbidden, so dispose of any supplies before the border. This apart, the border control is slow but usually very civil, and as long as everything is in order all should run smoothly.

The direct and most travelled route leads to Tabriz and Zanjan, then south to Esfahan via Hamadan, avoiding Tehran - unless of course you want to tackle some of the worst traffic jams in Asia. Esfahan is the cultural centre of Iran, and still houses some of the most valuable craft workshops and bazaars of the Middle East. The Shah Abbas Mosque is spectacular, with turquoise-blue ceramics covering its domes and minarets. In the summer months, a rewarding journey will take you north of Tehran and over the Albarz Mountains to the Caspian Sea, before heading south through the Kavir Desert and the Dasht-e-Lut to rejoin the route to Pakistan.

You could consider an alternative route from Iran into what is commonly known as Central Asia, though reports on the viability of taking your own vehicle on this journey are mixed. From the north-eastern Iranian city of Mashad, capital of Turkmenistan, the main route heads east to Bukhara and Samarkand in Uzbekistan. However, for several years the Iranians have apparently refused to offer visas allowing foreigners to leave or enter via this route. There are presently no overland operators running vehicles on this route.

Afghanistan is still considered a no-go area for any form of overland travel, as the Taliban regime in power is in conflict with regional resistance groups. In addition, the country is heavily landmined following the Russian involvement in the Eighties, rendering many areas unsafe.

Back at Esfahan, a day's drive south will bring you to Shiraz, the garden city renowned for its hospitality, and the nearby ruins of Persepolis. This 2,500-year-old city was built by the Persian king Darius the Great, only to be destroyed by Alexander the Great around 300 BC.

You now follow the old southern trade routes across Dasht-e-Lut, via Kerman and Zahedan. The way is punctuated with caravanserai and desert fortresses; one of these in particular, the mud brick city at Bam, is still virtually intact and is a must to visit. Crossing the Baluchistan desert is now the only viable route into Pakistan, but this is a highly sensitive region in which you need to proceed with caution, avoiding any night-driving and camping out. You should also avoid any form of disagreement or conflict, no matter who is at fault. The volatile Baluchi people are usually armed and often smugglers, so diplomacy is called for in order to avoid any problems.

The rather chaotic border post at Mijaveh/Taftan is usually straightforward and travellers are often welcome to sleep overnight at the Pakistan customs post.

The construction of the bitumen road through the desert to Quetta is now at last complete, but constantly drifting sand and seasonal flash floods often have an adverse effect on conditions.

Quetta is very much a frontier town: a colourful mountain oasis, bazaar and crossroads for traders and smugglers alike. While it has very little in the way of architectural interest, the people who throng the streets and markets - Afghanis, Baluchis and Pathans - provide lively colour and character.

Following ancient nomad routes into the Indus Valley, Pakistan's lifeline, the most direct route now takes you via Sukkur and Multan to Lahore. If time and resources permit, however, a route into Pakistan's northern frontier region is a must, especially during the summer months (June to September).

The frontier region of north-west Pakistan, bordering on Afghanistan, is tribal and access is restricted. If you intend to visit the north, follow the Indus Valley via Dera Ismail Khan to Khot and on to Peshawar. At Peshawar you have the choice of exploring the North-West Frontier (home to peoples with such firmly established indigenous cultures that time seems to have stood still here) or taking the Raj-built Grand Trunk Road down to Lahore. From Peshawar you can also explore the Khyber Pass and the Swat Valley. Further north, Chitral and the Kalash Valleys are inhabited by the Kafir people, possibly descended from Alexander the Great.

From Peshawar, this route crosses the Indus river, overlooked by the mighty Attock Fort, before continuing to to Rawalpindi and Islamabad, Pakistan's satellite capital. From Islamabad another excursion is possible, this time north to the Hunza Valley and the Karakorams. Although the land border is open over the Khunjerab Pass to China and Xinjiang Province, this crossing is possible only on local public transport (the Chinese authorities still make it very difficult to obtain permission to enter China with foreign-registered vehicles). Public transport provides an interesting alternative route, passing via Kashgar and Urumqi to follow the ancient Silk Route through the lands of Ghengis Khan and on to Beijing and Shanghai.

From Islamabad continue south again, into the heart of the Punjab to Lahore, with its Moghul Red Fort and Shalimar Gardens. A bustling thriving city, Lahore is an ideal centre in which to make any mechanical repairs before entering India.

From Lahore the Grand Trunk Road takes you the short distance to the Wagah/Attari Road border with India. Here strict times of opening and rampant bureaucracy welcome you to India. You will immediately see and feel the change.

India and beyond

This fascinating country of diverse cultures, terrains, languages and religions has a population in excess of 900 million people, making the largest democracy in the world. Though predominately Hindu, it nevertheless has the largest Muslim population of any country in the world. The history and sights of India offer the overland traveller unique itineraries, whether pursuing the direct route to Nepal or following the Grand Trunk Road to its destination at Calcutta.

The first stop in India, in the wealthy state of Punjab, is Amritsar, the centre of the Sikh religion. The holy shrine to the Sikh faith is the Golden Temple, which welcomes visitors and pilgrims alike. Now the route takes you on to Delhi - and from here the choice is yours.

In autumn, winter and early spring, the colourful desert state of Rajasthan makes a rewarding diversion; some head further south to Goa and its beaches, or further still to the hill stations of the south.

During the summer months, the Himalayan foothills offer some respite from the heat and the effects of the monsoon. Simla, the Kulu Valley and Manali are wonderful spots in which to relax, or try venturing further north into Ladakh.

Following the overland route, do not miss Agra and the Taj Mahal, the highlight of any journey to India. Head east to Varanasi on the Ganges, sacred to Muslims and one of the holiest places of the Hindu faith, with early morning cremations on the historic ghats. Nearby, at Sarnath, is the site of the Buddha's first sermon.

The traditional route of the past 30 years or so takes most overlanders to the Himalayan kingdom of Nepal and to Kathmandu. Once the cloistered capital of a relatively secluded kingdom, it is now a busy tourist centre offering climbing, trekking, and rafting expeditions. With its friendly people and its splendid scenery and climate, Nepal will always provide a welcome rest at the end of a long journey, or a refreshing pause to those venturing further.

During the summer months, many of those who choose to continue cross the passes of the Himalaya on to the Tibetan plateau, slipping in through the back door of China. Entry is still generally restricted to organised tour groups with a minimum of five people, however, and again it is impossible to enter with foreign-registered vehicles without very special (and costly) permission. The alternative route via Bangladesh and Myanmar (Burma) is not yet possible, but times are changing: recent reports indicate the opening of some land borders between Myanmar and Thailand.

In the future there may yet be the possibility of a complete land route to Singapore, and (with a few sea crossings) on to Australia. London to Sydney: now that would be a classic overland journey.