Spent a long weekend, three days, in Wroclaw. I'd been planning a trip since a coworker told me about the city, and the Christmas market was the added incentive, It's large, bigger than Heidelberg's, and spreads out in all directions from the Bazylika Mniejsza pw. Św. Elżbiety (St Elizabeth's Church). There are four major sections, each with a large area centered on a hot beverage stand. I say this because they have multiple options, mulled cider, spiked chocolate, wine, etc. There are also many vendors of other beverages, mostly with a proof rating. And the food, while similar to that served to the west, is different. Yes, you can get a "bratwurst", but again, there are options, and most come with a very different bun, and smothered in grilled onions, and/or peppers. (My favorite was the "Slab of Bread", an inch thick slice about 12"x4", cut from a huge loaf, covered in cheese and thick sliced kielbasa, baked, and then garnished with onions, or pickles, or something else.)
There were some rides, and a couple multi-story fun houses, but nothing like the carnivals that are run in some places. Mostly these were for the pre-teens. They also had a number of holiday puppet shows and animations in small huts, traditional fairy tales like "Red Riding Hood" being the most common themes. Lot's of street musicians were out also.
Prices were lower than what I've found this year in Germany, the one exception being the cost of the annual mug, which was close to 5 euro (20 Zl). A footlong sausage was 10 Zl, and I can't think of anything that ran over 20. Exceptionally good doughnuts and cinnamon rolls could be had for around 5.
The one thing I did have an issue with was it's almost impossible to find a beer at one of the stalls. But since the Zabka chain has dozens of locations around the market and Old Town, that's where everyone wanting a beer, without going into a bar, patronized. The local beers are very good.
This is a very popular Christmas market. There were dozens of guided tour groups walking the city during the day, mostly Polish and Eastern European (I only saw one with an English guide, and it was less than 20 people). After dark the market gets crowded, wall to wall people, and the popular restaurants and bars will have lines outside. You'll want to get tickets to the major museums in advance; the Panorama, for example, was completely sold out the entire two weeks around my visit. (The Military Museum, on the other hand, was almost empty.) There were also major crowds around the main churches.
There are a lot of holiday decorations away from the Christmas market. The University has a fantastic, huge, Christmas tree (near the fencer fountain), the small market square has another (not as good), and just about every public building has something special.
And then there's the gnomes. I found over 30, and while some are pretty obvious, others are less so. Locals don't pay them any attention, but the tourists do.
Wroclaw is a very easy city to walk, provided you pay attention, as there's an issue with missing cobblestones on every block. The city is flat, with a number of bridges, and it's noticeably less well swept up compared to most German cities. The walk along the river is really well done, part of a major flood control project, and very popular with runners and dog walkers.
The covered market is a great place to get fresh produce, pastries, local sausages and cheeses, and it opens at 8am. I found it perfect for a breakfast of coffee and whatever looked good, which I took across the street to eat while watching the swans on the river.
I stayed at the Wroclaw Hotel and highly recommend it. It's near the University, the covered market (Hala Targowa) is a 5 minute walk, there are a couple antique shops, half a dozen art galleries, and the Military and Archeologic Museum (in the same building) all right there. Just look for the 2 story high chair.