Beijing's favorite playground on ice is not just for kids. Grownups outnumbered the children at Houhai on Saturday afternoon, circling the famous city tourist attraction's frozen lake on ice skates and - my new favorite - ice-bikes.

Not all of us are graceful on skates or daredevils on skis on the slopes come winter. But on an ice-bicycle, I mastered it in one minute. So did a group of 5-year-old children piled on one in front of me. That did not stop me from later bragging about my ice-bike skills to friends.

Admittedly, it's almost impossible to fall over on an ice-bike. These are converted bicycles with the front wheels removed. The front wheels have been replaced with runners, and runners also are attached to metal pipes placed squarely over the back wheels, which makes them boxy enough to remain stable on ice.

Ice-bikes are not the only fun invention on the ice at Houhai. Ordinary chairs are fitted with runners, and riders use modified ski poles to steer their way from one side of the lake to the other. Groups of people on ice-chairs will grab on to chairs in front of them to form Chinese-style conga lines to snake around the ice, laughing at each other and smiling at the applause of onlookers.

This may sound like no big deal to veteran Beijingers, but I never saw anything like ice-bikes and ice-chairs back home in the US. If I find out there's no copyright, I plan to send photographs to my nephew who lives in a cold-weather state to patch together copies and introduce these novelties to his neighbors. Of course, I will insist that he name his makeshift copies Beijingers.

I'm not from a cold-weather state, but I have discovered that the freezing winds of winter in Beijing are no obstacle to having fun. At Houhai, and at frozen lakes around the city, residents of all ages put on ice skates or take to the ice on less traditional inventions like ice-chairs to make a happy festival of a cold afternoon.

At Houhai, the whirling skaters and ice-machine riders can skid to a halt at amusement park-style games and win prizes, or stop at hot drink stands also parked right on the ice.

None of this fun is expensive, either. It costs 10 yuan to walk onto the frozen lake, and 20 yuan or 30 yuan to rent an ice-bike, ice-chair or modified amusement park-style bumper car. There's a 100-yuan deposit if you rent an ice-ride, but you promptly get it back as soon as you sign back in your vehicle to the English-speaking ticket sellers.

There is terrific scenery from the ice as you navigate your way around the edges of Houhai for views lining the lake of the imposing Bell and Drum towers and converted hutong - ancient buildings now housing an extraordinary range of inexpensive to high-end bars, restaurants and shops.

But the best action for photographs this time of year is on the ice, where you see cheerful grandparents hugging children wearing brightly-colored winter outfits on ice-bikes, watch local and expat couples gracefully sliding by and catch the sight of yet another ice-chair conga line formed by dozens of people on ice-chairs.

The silliest things on ice at Houhai are over-sized, battery-operated, sneaker-wearing toy animals just big enough to pull small children in attached miniature carriages at very slow speeds along the edge of the frozen lake.

January is the time of the year when you tend to hear grumbling from new and veteran Beijingers forced to don sweaters, heavy coats, mittens, scarves and hats to warm themselves outdoors. But now I've learned it's also the time of year to make the best of it at a nearby frozen lake, because who cares if it's cold outside when you're too busy having fun riding an ice-bike?