For eleven months of the year, the retail traffic is one-way as the good burghers of this prosperous North-Rhine Westphalian city drive the short distance over the Dutch border to the shopping towns of Venlo or Nijmegen, to historic Maastricht, or to the hospitable city of Utrecht for bargains and Sunday shopping. Not in December.

In December the yellow number plates of the Netherlands clutter the roads and car parks around Düsseldorf - a sure sign that the charm of the Christmas markets is working yet again. Why they - and with them many thousands of Brits and Germans from the hinterland - flock to the city becomes clear as you explore the markets.

Glühwein and herring anyone?

During the weekday the markets are fairly quiet, gathering pace as the after-work crowd brave the chill December wind to stand around sticky wooden tables clutching at a warming mug of Glühwein - the drink of choice, a hot fruity red wine. The stalls are not usually too packed at this time, a good chance to beat the mad weekend crush and pick up some gifts.

Disappointingly, they shut quite early - in the Altstadt the stalls are mostly all closed by 9pm, with only one or two of the food stalls lingering open for the slow-drinkers. Schadowstrasse is a little more relaxed, but still, by 9:30pm all is basically over. The weekends are another matter entirely. In the afternoon the narrow pathways that wind through the markets are crowded with locals and visitors alike. Many travel companies offer Christmas markets packages and more English voices waft through the air over these advent weekends than one hears during the rest of the year combined. Many come for the quality hand-crafted decorations, others just for the atmosphere - and a chance to explore some of Düsseldorf's famously swanky shops. Actually shopping at the stalls is a battle at these times, even getting to them is a challenge - although everyone is in a jovial frame of mind and the usual barging and grumbling is put aside in favour of gentle shoving and mild mumbling.

The absolute best time to go - if you actually want to browse and shop - is Sunday evening. The markets are often all but deserted and you can have the place to yourself. Stallholders are happy to talk - explaining how this bracelet was made, or from where these glass decorations were imported. Round by the incongruous Finnish-section (the only country to have its own bit of market), you can feast on salmon, or pick up a last minute herring-related bargain at the end of the day.

Crowded Cologne

The sheer volume of people conspire to make the Cologne markets more of an ordeal than an enjoyable day out. The city's "Bethlehem" market - a strange faux Palestinian-style open-air structure - houses more food, mostly (from what little I could see) of Middle Eastern origin, a cuisine already incredibly popular in Germany thanks to the large Turkish population. A plaque usefully announces that Cologne is twinned with Bethlehem, and with Liverpool. Could Liverpool and Bethlehem be twinned as well? Perhaps John Lennon had even more in common with Jesus than he thought!

Indoor shopping

The main stores themselves have Weihnachtsmarkt sections where you can stock up on the ginger-laden Lebküchen, or marzipan-filled chocolates. Shops appear crammed with colour-coordinated decorations, often at extremely good prices. And every time you step back outside into the bracing cold, the smell of grilled sausage is mingling with the thin December fog.

Many German towns have these markets; Nürnburg's are perhaps the most famous. Some of the less spectacular ones have devolved into selling globalized marketware: mobile phone covers and personalized key rings mass produced in a Taiwanese factory. Others focus on twee decorations, or may only be in situ for one weekend.

Düsseldorf's markets are ideal - small enough to avoid the overcrowding of Cologne, but large enough to rise above the plastic merchandising of some others. And that is why, every December, the Dutch drive to Düsseldorf.