It has taken a long time for the local holiday business to latch on to the concept of eco-tourism, even though it is the global industry's fastest growing sector at a time when competition for tourist dollars has never been keener. The challenge today is to persuade people that there is more to Hong Kong than glass towers and glitzy shopping malls. Even if eco-tourism never takes up more than 20 per cent of travellers' time, it could mean a minimum of an extra day's stay for most visitors. That would raise hotel occupancy rates, and extend the benefits of tourism into rural areas. The beauty of the SAR's 230-plus islands is one of the travel world's best kept-secrets. The New Territories has bays and hills, streams and forests as lovely as anywhere on the planet. The contrast between the solitude of the mountains and the frenzy of Central could not be more marked, but most tourists seldom see the outlying areas. Now a booklet has appeared, thanks to joint efforts by tourism and government agencies, to guide visitors into these wilder places. It tells where to find the stunning scenery, bird and butterfly life, and how to finish the day by dining al fresco in an out-of-the-way village. But this effort will be wasted unless the public recognises the importance and fragility of the countryside. Every weekend, thousands of picnic parties pour into the country parks, yet most have almost no appreciation of their own role in preserving the beauty which surrounds them. Otherwise, they would not leave their barbecue sites so deep in debris that special clean-up squads spend the rest of the week tidying after them. It is a mystery why people so fastidious about personal cleanliness can be so uncaring. Litter bins at barbecue areas remain largely empty, while every inch of ground around them is covered in foam containers, wrappers, plastic bottles and metal forks. Any eco-tourists seeing the aftermath of these weekend invasions would be repelled by the sight, and perhaps reluctant to visit again. The tourist industry cannot afford to have them returning home with that image among their memories. Before Hong Kong launches itself into this niche market, the authorities must find a way to stop local disregard for the SAR's most precious asset. Perhaps one answer is more patrols and stiff on-the-spot fines. Perhaps returnable park entry fees for walkers who show they are taking their litter home with them. At present, notices to that effect are ignored, but perhaps people would change their ways if faced with financial penalties for anti-social behaviour.