HOW COULD a short, nondescript thoroughfare in an unlovely part of an unbeautiful city possibly be one of the 20 notable streets of this century? By fuelling the backpacker revolution, making travel more affordable, and - crucially - accessible. You may have been trudging through South East Asian jungles for months, or be a novice fresh off the plane from Britain. Either way, as soon as you turn the corner into Khao San Road you know you are in safe hands.

The home straight of the world's backpacker circuit is lined with cafes offering dishes and drinks that will alleviate the worst cases of homesickness, and, through internet terminals, instant contact with your electronically furthest and dearest (except during odd blips like last Monday's shutdown of the Hotmail network).

Behind this frontline you can find a range of places to stay, from downright dingy to air-conditioned comfort; better not choose the latter if you want to retain any credibility in the "I can live more cheaply than you" conversations that resound up and down the street.

Frequently the backpacker banter is drowned out by the shrill whine of tuk-tuks (three-wheeled "taxis" that look like an eccentric cross between a Reliant Robin and a bus shelter), which bring their human cargo to the world centre of fakery. To help cut your costs, there is a roaring trade in fake Rolexes, copies of designer T-shirts and dodgy student ID cards. The latter can be (fraudulently) used to get cheap air tickets from the travel agents in Khao San Road, to anywhere in South East Asia and beyond.

The street owes its celebrity to Bangkok's geo-political positioning in the heart of the South East Asian travel web. When Tony and Maureen Wheeler, founders of Lonely Planet, set off Across Asia on the Cheap in the early Seventies, they found that one or two cheap hostels in the Khao San Road were catering for the embryonic backpacker business. Every street in every big Asian city, from Kathmandu to Penang, has such a road, but Khao San Road was the original and is still the busiest.

Before you travel on to Vietnam, Cambodia or Laos, it makes sense to establish a base camp here. Visas and tickets are cheaper and easier to obtain than in many cities, and - equally important - the travellers' network means you can pick up the latest tips from people who have been there, done that, want to tell you all about it and, by the way, do you want to buy some surplus Vietnamese dong? Or some dope? Or ... if you think it is time to shed your hippie image and make a fresh, smart start, then there are plenty of tailors who will compile a suit for you in 24 hours. But don't be surprised if it falls apart as soon as you are safely across the border and into Malaysia.

Simon Calder