What does the 3N in the tourism industry mean?

The so-called "static tourism" means tourists go hiking together to avoid the noisy cities and towns and go to the rarely visited nature to quietly "soak" for a few days. The characteristic of this kind of tourism is to avoid tourist attractions and cultural landscapes that are crowded with tourists, and go to nature such as primitive forests, grasslands, mountains, river valleys and lakesides. Instead of running around, you only set up camp at the destination. Stay for a few days, make your own meals, live in an RV or tent, and during the trip everyone does their own thing according to the prescribed plan... Some sit on the grass for a long time, quietly feeling the breeze, sunshine, and accepting the blessings that nature bestows on mankind; some go to the wild to relieve physical pain and fatigue, or mental anguish and sorrow. They silently accept its moisture in the embrace of nature, and heal physical or mental wounds in wind and rain baths, sun baths, flower baths, forest baths, river baths and lake baths. ..." The above-mentioned "static tourism" and "looking for wild interests" are the latest tourism fashions in the 21st century, which are the "3N" tourism that the Western tourism industry has identified as the tourism development trend in the 21st century. (Nature, Nostalgia Nostalgia, Nirvana). They believe that in the past, people were keen on tropical seaside vacations, enjoying the warm sunshine, blue sea and comfortable beaches, but today they are tired of the fast-paced modern city life and suffer from modernity. For urban residents suffering from urban diseases, what they yearn for is to let their polluted souls bathe in nature and immerse their hearts in the harmonious and perfect harmony between people and nature and people in the countryside. In nostalgia (Nostalgia), so as to integrate one's spirit into the paradise on earth (Nirvana). Therefore, "3N" tourism will gradually replace "3S" tourism.