Why go now?
Because Istanbul is arguably the greatest city in Europe, and Asia. Because you are 10 degrees closer to the Equator. And because you can become a Turkish lire millionaire by exchanging just pounds 3.22.
British Airways (0345 222111) and Turkish Airlines (0171-499 4499) fly twice a day from London Heathrow to Istanbul; Turkish Airlines goes three times a week from Manchester. Turkish Airlines has a special offer from Manchester of pounds 150 return (including the swingeing pounds 30 tax). If you travel on the 5pm flight from Heathrow you pay pounds 194 return, including tax.
Get your bearings
You would be forgiven for thinking that many of the city's 12 million residents have come to the airport to meet you. If you're in a rush and feeling flush, get a taxi into town. Pick it up from the official stand and you should pay what's on the meter, between about pounds 7 and pounds 10.
Otherwise, offer a couple of pounds for the short ride to Yesilkoy station and take the wonderfully ramshackle railway around the coast, and past Topkapi Palace to Sirkeci station - which opens up to the heart of European Istanbul. The centre of the city is Sultanahmet Square, where you'll find the tourist office and a good free map.
The Sultanahmet area has a huge number of hotels in all price ranges. Claire Gervat stayed at the Mavi Guest House (00 90 212 516 5878), round the corner from Topkapi Palace, where rooms start at pounds 9, including breakfast.
Simon Calder paid pounds 10 a night at the Aladdin Guest House, just south of the Blue Mosque (00 90 212 516 2330). There's also a former prison nearby, converted into a Four Seasons hotel. Current guests pay upwards of pounds 130 for a room, but they do, at least, have the option of checking out when they want. A more affordable option is the nearby Hotel Empress Zoe (00 90 212 518 254), simple and elegant, with doubles from pounds 40.
Take a ride
The best Bosporus crossing is a source of great debate, and the only way to form a view is to do some research: criss-cross the neck of water between the Mediterranean and the Black Sea at 25 pence a time, and revel in the ever-changing views.
Take a hike
Many of Istanbul's cultural attractions are within easy walking distance of each other, so you can combine culture with mild exercise. Starting in Sultanahmet Square, take a short stroll down the Hippodrome, now a tiny park with just a few reminders of its chariot-racing days. Half-way down is the Museum of Turkish and Islamic Art, remarkable as one of the few places in Istanbul where you can look at carpets without having to buy one. From there you can go round to the old bazaar and the Mosaic Museum, then through an archway to the front of the Blue Mosque and across the park to Aya Sofia. If you have any energy left, head round the corner and past a row of restored Ottoman houses, then follow the tramlines down to the hectic ferry terminal at Eminonu.
Lunch on the run
If you've made it down to the waterfront, grab a snack from one of the nattily dressed boatmen who moor among the ferries and cook up fish on precariously bobbing grills. It's an enjoyable sight, and even more heartening when it comes to paying for your sandwich, a snip at 35 pence. There are also the ubiquitous kebabs, spiced and delicious, a far cry from Britain's flabby imitations.
Head back up the hill to Topkapi Palace and an insight into life as an Ottoman ruler, or a member of his household. Don't miss the views over the city from the terraces in the fourth courtyard, or the ornate Baghdad Kiosk. The bad news is that the most interesting section of the palace, the Harem, can be visited only on a guided tour, which you have to book half-an-hour beforehand. This wouldn't be such a problem if the group were smaller, or if the guide were not trying to conduct the tour in two languages at once. Ignore the words and concentrate on the lavish tiled, painted and gilded interiors instead.
With around 4,000 shops, the Covered Bazaar must have the largest range of retail opportunities on the planet - particularly of old silver jewellery, carpets, leather goods and designer fakes. The displays could tempt even Scrooge into extravagance. Your only obstacle to window-gazing in the bazaar will be the determined shop owners trying to lure you inside and part you from your cash. On the other hand, with the current exchange rate, why resist?
You'd think that Sultanahmet would be teeming with waterside bars, where you could while away the hours before dinner. But the local traders, usually so good at thinking up pleasant ways for visitors to spend money, have missed out on this one. Instead, head up the Bosporus to Ortakoy (on the European side, beside the private university) to check out the drinking haunts of Istanbul's trendy liberals.
Turku Cafe and Bar, in Beyoglu at Imam Adnan Sok 9, serves up traditional food in hearty portions to an appreciative crowd of locals. The other main attraction is the live music: Turkish folk songs sung with feeling, and not just by the musician (there's only room for one). A huge meal with a beer shouldn't cost more than a fiver.
Sunday morning: go to church
The Blue Mosque is, along with Aya Sofia, the city's defining landmark, and even if you think you don't want to go inside there are plenty of persistent guides who will try to persuade you otherwise. Inside, the walls are largely covered with the blue tiles that give the building its name, but the main impact is from the sheer size of the place. The solemnity is rather spoilt, however, by all the bare-footed tourists carrying their shoes around in green plastic bags.
Just across the road from the Blue Mosque is Lale Restaurant, whose main claim to fame is as the Pudding Shop in Midnight Express.
Pity the poor hippies who turn up there now in search of authentic seediness. It looks much the same as the other restaurants in the street, with the exception of its incongruous tartan tablecloths.
A walk in the park
People do not go to Istanbul to enjoy a gentle stroll amid pleasant parks and gardens. But if you want to leave the city behind, take a taxi to the edge - the crumbling, ancient walls that protected the western flank.
Make for Tekfur Saray, the doddery Byzantine palace of Constantine Porphyrogenetus. As you wander through its wide open spaces, you feel a sense of emptiness and isolation that eludes you everywhere else in Istanbul.
The icing on the cake