My curiosity was satisfied when I saw the men humping the blocks onto the slopes that surround the water, where they proceeded to use them to build a set of "bobsleigh" runs. Some of these were equipped with extra bumps and bends to add a little spice to the experience. Once the runs were complete, you could hire an inner tube from a car tyre at a price of ten yuan per hour, and have as much fun as you could take.

Adults and kids share the fun of sledging. [by David Ferguson]

The total drop on the runs is about 20 metres – enough to be exhilarating without creating any serious risk. Your momentum at the bottom will carry you across to the other side of the lake. There is a kind of glorious anarchy to the things – whatever health or security regulations exist seem to be applied with the lightest of touch. Children as small as three (including my own) are dispatched over the edge on a tube with nothing more between them and disaster than their thick winter clothing and an entreaty to "hold on tight".

Bumps and bruises – and the accompanying faces streaked with frozen tears – are common enough. I saw a few near things, but never any serious accidents, although a mother told me that her daughter had once broken a wrist.

I was left to reflect on how such an amusement would be managed in the over-regulated UK – a swathe of local authority-sponsored rules; crash-helmets, elbow, and knee-guards by order; unlicensed slides destroyed by government operatives; all financial profit and prospects of fun wrung out of the thing so that it wasn't worth anybody's while… no doubt it will come to China in due course. This year the runs are made of heaped snow and much smaller ice-blocks – just as effective, but they don't feel nearly as claustrophobic.