|(Provided to People's Daily Online)|
(3) Beautiful environment
Pu'er is the most well-preserved and largest oasis on the Tropic of Cancer. With an annual average temperature of 15.3-20.2 degrees Celsius, it is free from winter cold and summer heat. The concentration of its negative oxygen ions goes beyond Grade 7, the highest standard for this parameter in the world. In the downtown of Pu'er, there are 850-12,500 negative oxygen ions per cubic centimeter. It is for these reasons that Pu'er is deemed as "the spring amongst springs, and the spring city amongst spring cities" and one of the most livable places for human kind, and reputed to be a "Pearl of the Green Sea" and a "Natural Oxygen Bar". As the construction of a "characteristic, charming, cultural and livable city" is accelerating, a "green and eco-city surrounded by forests outside it and decorated by forests, flowing waters and green mountains inside it" will be presented before the world.