Qingchengshan-Dujiangyan National Park
Qingchengshan is one of the ancient cradles of Taoism in China. The mountain complex is home to both many Taoist and Buddhist temples and sites along the paths that wind up to its peaks. The area is snow-free all year round and is known for its peaceful quiet (this of course excludes the Chinese tourists that flock there on major holidays and the incessantly loud blasts of bus horns along major roadsides). The back entrance to the mountain is much less touristy and much more quiet and should be visited first by those who have hiking as their priority. It contains many links to over 80km worth of very green and lush hiking paths including a few small chairlifts.
The Dujiangyan Irrigation system is a marvel of Chinese imagination. Before the completion of Dujiangyan, the plains around the Min River were prone to flash flooding. This was due to the fast moving river flowing down from the mountains and meeting level ground. It was in the Warring States period about 2,200 years ago, that the engineer Li Bing and his son led the construction of the Dujiangyan irrigation system. This allowed the taming of the river and the irrigation of the surrounding lands.
For more information see:
- Qingcheng/Dujiangyan (China) (2000), UNESCO World Heritage. 
- Taming the Floodwaters: The High Heritage Price of Massive Hydraulic Projects (2005), China Heritage Project. 
Wonderful midrange mist covered foothills including lots of bamboo.
Flora and fauna
Influenced more by the surrounding mountains than the Sichuan Basin, the area is subject to frequent rain and fog. Bring rain-gear! Wear layers.
About 1-1½ hours by bus from Chadianzi Bus Station in Chengdu. The bus drops you off at the front gate, which is not actually the start of the trails. A new express train service now runs from Chengdu's North Train Station, taking about 45 minutes. It is best to buy tickets the day before you depart, as they often sell out ahead of time, even on weekdays.
The entrance fee is ¥90 (2011) but if you get the Panda Card (shengmao card) in Chengdu, which is designed to restore tourism after the earthquake, you can get in for free (until December 31 2009).
You can either climb to the top which takes around 3 hours or take a boat across the lake (¥5) to a ropeway (¥35 one way ¥60 round trip) which will get you there sooner depending on the queue time (which during a holiday could approach and 1½ hours or more). A sedan chair can also be hired for ¥100 or more in which two men carry you up the mountain.
Qingcheng Mountain is known for its Daoist temples.
If you are looking for more natural beauty then Qingcheng Hou Mountain is where you should head. There are still several trails closed due to landslides caused by the earthquake (6 October 2009).
There are shrines for many Daoist masters and Chinese Medicine doctors including Lao Zi and Sun Simiao. If you are expecting a spiritual experience DO NOT come on a Chinese holiday or the only quiet time you will have to enjoy it will be if you are lucky enough to find a bed in the monastery and wake up at sunrise before the tours get there.
You can stay at many of the monasteries on the mountain. Some of them have recently been upgraded to 3 star status and accommodations can be in bunk style for around ¥40 to twin private rooms at ¥180. Keep in mind that during the Chinese holidays you may not find a bed or might be stuck with one of the higher priced choices.
Pick up the bus back to Chengdu a little bit downhill of the tourist center in parking lot. "Chengdu" will probably NOT be written in pinyin so you will have to ask the driver. The Chengdu bus is usually closest to the top of the parking lot though and does not leave until it is full. Cost back is ¥20 and may not bring you to the bus station you want to be at in Chengdu.
Another alternative is to take the brand new high speed rail link back to Chengdu. It is much faster and convenient than the bus which cuts your travel time in half and delivers you in first class conditions to the North Train Station. A bargain price of only 15/20 Yuan. A taxi to the train station from the Qingchengshan parking lot will cost around 20 Yuan.
You may want to visit Dujiangyan Irrigation System after a trek up the mountain, which is the last stop for bus number 101 and leaves from the Qingchengshan parking lot. It costs two and a half Yuan and is just a forty-five minute bus ride away. The high speed train bound for Chengdu also leaves from Dujiangyan.