October 31st, 10pm, and on Bangkok's Kao San Road the street party was in full swing, with witches and warlocks mingling among the crowd, and giant cobwebs and spiders decorating the backpacker hangouts. Beer was 50 baht a bottle from converted camper van bars, and from a stage halfway along the road a hairy rock band added a thumping soundtrack. Street stalls sold fried bugs: grasshoppers, scorpions, cockroaches. This was my introduction to Bangkok; a few hours before I had been wandering around Kathmandu, snapping some last-minute photos (including some of a rather frisky bull that was wandering around charging at people - I was glad to have a zoom lens...) and bouncing along in a clapped-out old taxi to the airport. In contrast, the taxi that took me from Don Mueng airport to the centre of Bangkok was new and air-conditioned, the expressway was smooth and fast, and there were skyscrapers and Starbucks as far as the eye could see.

After Nepal, the bright lights of Bangkok were a kind of sensory overload, but luckily there were a couple of familiar faces who helped to ease the culture shock. First there was Paul, my friend from London who is working as a teacher in Bangkok, and had very kindly offered to put me up in his flat off the Sukhumvit Road. He's been in Bangkok for more than a year, and despite insisting that he can't speak Thai, still managed to have a halting conversation with the taxi driver during the journey from the airport. Then there was Anna, former office-mate and research colleague from my time at South Bank University in London. Later, we would be going trekking together around Mae Hong Son, but before that, Anna and her friend Renée from San Francisco would be spending a week on the white sands of Ko Chang. On her first day in Bangkok, I found Anna stretched out on a sun-lounger by the pool of the Royal Hotel, getting in some practice for the beach.

Anna and Renée had a day in Bangkok before catching the night bus to Ko Chang, so I joined them to do a little of the tourist trail. The Grand Palace was spectacular, but full of huge tour groups, even early in the morning; Wat Po was quieter, and away from the central temple it was possible to escape from the worst of the crowds. The first thing that struck me about these two sights was the sheer amount of gold that was everywhere - gold paint on the temple roofs and the giant chedis (stupas), gold leaf stuck to Buddha images by worshippers. In the strong tropical sun, the gold was as radiant as the neon of the city at night; in contrast to the weather-beaten stone of the Nepali temples I had seen, Bangkok's star attractions looked pristine, maybe even a little clinical in their perfection. Less flashy but more atmospheric was Wat Arun, the "Temple of the Dawn", just across the river from Wat Po - in fact it looks even better when seen from a riverboat.

When surrounded by hoards of tourists, it’s easy to forget that temples such as Wat Po and Wat Phra Kaew (in the grounds of the grand palace) are some of Thailand's holiest religious sites. It's the same situation as in famous European churches: worshippers perform their devotions surrounded by noisy camera-snappers. And just as in Europe, religion attracts free enterprise. Some of the strangest examples of this I saw were the stalls, generally around the less touristy temples, where stacks of caged birds are on display. For 60 or 70 baht, one can set free a bird from its cage, thereby accruing merit or "good karma". I don't claim to be an expert in Buddhist philosophy, but it seems that someone has had to commit bad karma by putting the birds in the cages in the first place, so at best it's a zero-sum game. Maybe the stallholders get reincarnated as caged birds. The temples also have more than their fair share of lottery ticket sellers, presumably playing on people's perceptions that their luck has been enhanced by their acts of worship. Anomalies such as these seem inevitable - but they did not detract from the intensity and seriousness that I saw on the faces of those who were prostrating themselves before the golden Buddha images. I couldn't help feeling self-conscious and out-of-place whenever I took out my camera.

Temples during the day, sleaze at night: after the girls had left to catch the night bus, Paul showed me around Patpong. The area has made it into all the guidebooks as a Place To See, and so attracts as many curious onlookers as sex tourists. Patpong proper occupies two short sois (lanes) that run off Silom road, but to warm up we started on the Sukhumvit road at Soi Cowboy, a garish neon-lit street with a vague Country and Western theme, where giggling tourists mingled with leering Japanese salarymen and drunken Brits. A middle-aged Japanese man approached three identically clad girls outside a bar, examined the little name badges they were wearing, then disappeared inside with one of them. The place felt down-market and seedy, but things got a bit more stylish when we moved on to the main Patpong sois, which felt a little like London's Soho, with trendy bars scattered among the lap-dancing joints. Walking around, the famous touts were out in force, offering "menus" that all seemed to feature bananas, goldfish, and various kitchen utensils. The touts approached the farang (Western) women just as much as the men. But alongside the sleaze, there are some nice places to eat and drink in Patpong, so we parked ourselves in a non-dodgy bar and drank our beer as we watched the procession of people outside the window. We finished up at Radio City, a favourite hangout of farangs and expats, and got there in time to see a set by the Thai Tom Jones, who plays there every weekend (we missed Elvis, who was the supporting act). The crowd sang along, and the women chucked their knickers at him. Paul said that he came here a year ago and saw the same Tom Jones play exactly the same set.

I spent the rest of the week exploring the city - the quiet narrow lanes of the old Portuguese quarter, west of the river; the markets of Chinatown; a sunset view of the city from the top of Wat Sakhet (you can really see the smog from up there...) One morning I decided to get up early and take a walk through Lumpini park, a large green space in the city centre which is a popular place for escaping the traffic and fumes of the streets. At dawn, small groups of mostly elderly Bangkokians gather for an hour of Tai Chi, dance lessons or karaoke - the paths through the park are filled with them, each group gyrating at various speeds to the rhythm of cheesy electro-pop from a portable sound-system. They get to take a break from their exercise at precisely 8am, when the Thai national anthem is played from hidden loudspeakers across the park - the karaoke boxes fall silent, and everyone stops what they're doing and stands to attention. As the final chord dies away normal business is resumed, and the songs of birds once more become merged with cheap electronic versions of Beatles songs, to which the lines of pensioners clad in identical pink track suits continue their morning calisthenics.

Bangkok traffic is notoriously bad, and I was beginning to get tired of sitting at traffic lights that stayed red for ten minutes at a time. A quicker way around the city is by taxi-boat along the canals, or khlongs. The boats race along the water, throwing up dubiously brown spray, which sometimes speckles the clothes of the passengers. The seats are wooden benches that run the entire width of the boat, and since there is no aisle between them, the ticket collectors stand on a narrow wooden ledge running along the outside of the boat, and hold on to a metal rail on the roof. They duck when a low bridge approaches, but also wear helmets just in case they forget. As we neared one particularly low bridge it looked like we would never make it - then the driver reached down and turned a little wheel on his right hand side, the whole roof moved forward and down until it sat just a few inches above the heads of the passengers, the ticket collectors bent double, and after passing safely under the bridge the roof returned to its normal position. It felt like a Bond movie; the bad guys should have been chasing us in a boat that was not equipped with such an ingenious device. They'd try to follow us, trash their boat on the bridge, and Sean Connery would make a wisecrack such as "No need to lose your head..."

On Saturday, a week after I had arrived, it was the Loy Kratong festival. A kratong is a small arrangement of flowers, incense sticks and candles, and on the night of Loy Kratong (which is always held when there is a full moon) people all over Thailand set them floating on rivers and lakes. The offering is meant to appease the spirit of the river and ensure good luck for the year ahead, and of course it's also an excuse for a huge party - on the Kao San Road there was the same buzz of activity as on Halloween the week before. I met up with Anna and Renée who were back in Bangkok, and were raving about the beauty and laid-back atmosphere of Ko Chang. Anna had picked up a kratong at her hotel, so together we made our way through the throngs of people and managed to get to a pier on the river with the kratong more-or-less intact. Just about every boat operator on the river was running special (i.e. double-the-normal-price) dinner cruises, and the lights from all these pleasure-craft outshone the feeble candles of the kratongs. But it was the ritual that was important, so after finding a spot that was not too high above the waterline, Anna gingerly dropped the kratong into the river. The candle went out, but the float itself stayed upright, and the red glow of the incense stick faded into the distance as it drifted away. Superstitious nonsense of course, but I couldn't help hoping that the promise of a year's good luck might turn out to be true.