More than half a million people a year flock to the Blue Mountains National Park, Australia's most accessible wilderness, to see its impressive peaks and ancient rainforest. But Australia is grappling with a dilemma: how to balance conservation with the need for tourist spending. Although it looks gorgeous and beautiful it is a park under pressure -- there are a lot of vulnerable species in this national park, said Tara Cameron, a local teacher and President of Blue Mountains Conservation Society. It's not a completely resilient piece of nature we can do anything with. Maintaining wilderness is an expensive business, and visitor numbers have fallen in recent years. The number of trips including an overnight stay has almost halved in the last decade, from 1.045 million in 1999, according to Tourism Research Australia figures quoted in the Sydney Daily Telegraph. They show an 18 percent drop in one year, from 687,000 in 2008 to 563,000 last year. The New South Wales government now wants to increase both tourist numbers and spending by attracting visitors interested in a more comfortable, less rugged experience. Its tourism strategy has attracted criticism for refusing to rule out development within the park. Mark Jarvis, who runs a hotel in Katoomba, the main tourist town in the Blue Mountains, just an hour and a half from Sydney, said: We 're very concerned because the