Beijing/Mentougou

Public transport service from central Beijing to Mentougou is mainly based on buses, many of them starting from Pingguoyuan (western final stop of subway line 1, temporarily closed for renovation in 2020) and stopping at Jin'anqiao (western terminus of subway line 6). Buses 336 and 931 run from Pingguoyuan (苹果园 píngguǒyuán) to Hetan (河滩 hétān) in Mentougou District. From there bus lines to most places of interest in the area can be taken.

For trips from Beijing city, renting a taxi for a day might be easier and less time intensive.

• 🌍 Tanzhe Temple (潭柘寺 tánzhèsì) (take bus 931 from Pingguoyuan subway station (Line 1) to Tanzhesi bus stop). Buddhist temple dating back as far as the Western Jin Dynasty (more than 1600 years ago). It is one of the oldest and largest temples in Beijing. The site is especially beautiful to visit in April when the surrounding Magnolia trees are in full bloom. ¥55 (students and seniors ¥30). 
• 🌍 Jietai Temple (戒台寺 jiètáisì) (take bus 931 from Pingguoyuan subway station (Line 1) to Jietaisi bus stop), ☏ +86 10 69806611. 08:09-17:30. Though not as popular and well-visited as Tanzhe Temple, this smaller Buddhist temple is definitely worth a visit. It was originally built about 1400 years ago, but its most famous features have been added later during Ming and Qing dynasties. A special attraction of this site are the huge pine trees, some of them being hundreds of years old. ¥45 (students and seniors ¥22). 
• 🌍 Mt. Lingshan Scenic Resort (灵山自然风景区 Língshān zìrán fēngjǐng qū). With 2300 meters in height, Mt. Lingshan is the highest mountain in Beijing. 

• 🌍 Cuandixia (爨底下) (Take the subway to Pingguoyuan in West Beijing. (About 1 hour from east Beijing. ¥2). Then take the public bus to Cuandixia. (about 2:20 hours. ¥13-18). There is a direct bus leaving from Pingguoyuan at 12:40, and one in early morning. If you can't catch the direct bus take the bus to Zhaitang, and take a private taxi to Cuandixia. The bus number is 929支, but be aware there are many buses with this number driving to many different places, so ask the bus driver if he drives to Cuandixia, or Zhaitang). A beautiful ancient mountain village. It is very small, only around 70 traditional court yards. It is renovated nicely and seems rather authentic. Go in the weekdays if you want peace and quiet. In the summer months the climate is nicer than in Beijing because of the cooler mountain air. In the winter it could be cold, but the beds are heated, so it is still possible to go. Do at least an overnight trip or you will spend most of your time in the bus and not have time to enjoy the peace in the beautiful village. You can easily spend one day in the village walking around on the mountain paths. It costs ¥30 for tourists to enter the Cuandixia area. 

• 🌍 Baiyu. A village with 100-200 traditional court yards. Baiyu is still rather unexplored, but it has plenty of guesthouses to sleep and eat in. Quality is good, prices low, the scenery is beautiful and the people friendly. Baiyu is about 6 km from the more well known ancient mountain village Cuandixia, so combining a visit to both places is a good idea. It costs ¥30 for tourists to enter the Cuandixia area. 
• Yanhecheng Great Wall (沿河城长城). A section of the Inner Great Wall, part of the double layer of Great Wall protecting Beijing. (updated Aug 2020)
• Pearl Lake. Good views of the mountain tunnels of the Fengtai–Shacheng railway which runs along the Yongding River. (updated Aug 2020)
• Mount Baihua (百花山). A popular day trip for Beijingers. It's a long 4km climb to the meadow at the top of Mount Baihua and the landscape is spectacular. On windy day a large misty cloud settles on top of the meadow which is filled with exotic flowers. (updated Aug 2020)