The Purple Mountain Observatory (Zijinshan Tianwentai) stands at about 267 metres on a northern summit of Zijin Mountain in Xuanwu District, Nanjing, Jiangsu Province, China. Founded in the 1930s, it is often described as the cradle of modern Chinese astronomy, and its historic domes, old instruments and terraced grounds make it one of the more distinctive short hikes in the city. The trail described here runs about 5 kilometres round trip from the Ming Xiaoling side and takes two to three hours.
Getting to the trailhead is straightforward. A taxi or Didi ride from Xinjiekou takes about 25 minutes and costs roughly 40 to 50 CNY, while visitors on the metro can take Line 2 to Xiamafang and continue by bike-share for about 3 CNY or on foot. Parking is limited, so public transport or taxi is the practical choice. No separate hiking permit is required for the wooded approach, though the observatory grounds keep their own opening times and some buildings may be closed to the public, so visitors should check the current status before setting out.
The ascent is about 200 metres and is technically easy. The surface is a mix of paved road, stone steps and packed earth, with dense tree cover that keeps most of the route shaded and cool. Exposure is minimal and there is no scrambling. Landmarks include the forest road climbing from the Ming Xiaoling area, the observatory gate and its historic domes, and viewpoints over the surrounding wooded slopes toward the city. A natural turn-around point is the observatory itself, from which visitors return by the same route.
Water sources on the trail are scarce, so visitors should bring water and snacks from the lower entrance area. There are no refuge huts, though a few pavilions and the observatory grounds offer places to rest and shelter from rain. Cell coverage is generally good but signs are mostly in Chinese, so an offline map is useful. Spring and autumn are the most comfortable seasons, while summer brings heat and mosquitoes in the forest.
| Distance | about 5 km round trip from the Ming Xiaoling side (~3 miles) |
|---|---|
| Duration | 2-3 hours |
| Difficulty | easy |
| Trailhead | Taxi or Didi from Xinjiekou about 25 minutes (about 40-50 CNY, ~$5.97-7.46); or Metro Line 2 to Xiamafang then bike-share (about 3 CNY, ~$0.45) or walk |
| Best season | April-May, October-November |
| Address | Purple Mountain Observatory, Purple Mountain, Xuanwu District, Nanjing (南京市玄武区紫金山天文台) |
Trail facts
- Trail area
- Zijin Mountain, Xuanwu District, Nanjing
What to bring
- Hiking shoes with grip
- Water and snacks
- Sun hat
- Offline map
Location
Purple Mountain Observatory, Purple Mountain, Xuanwu District, Nanjing (南京市玄武区紫金山天文台)
32.0653, 118.8281 View on map
Highlights
- Visit the historic Purple Mountain Observatory, an early centre of modern Chinese astronomy
- Walk a shaded forest road and stone steps with only about 200 m of ascent
- Enjoy viewpoints over the wooded slopes of Zijin Mountain
- Pair the walk with Ming Xiaoling Mausoleum at the trailhead
Tips for visiting
- Check observatory opening status before going, as access to buildings can change.
- Bring water and snacks; there are few places to buy them on the trail.
- Wear shoes with grip since the stone steps get slick after rain.
- Use bike-share from Xiamafang metro (about 3 CNY) for the approach if the weather is good.
- Apply insect repellent in summer when mosquitoes are active in the forest.
- Turn back at the observatory if rain sets in; the descent follows the same paved route.
When to visit
April to May and October to November are the most pleasant. Morning starts avoid summer heat and the busiest hours on the Ming Xiaoling side.
Accessibility
The route includes steps and uneven forest paths and is not suitable for wheelchairs. Parts of the paved approach road may be manageable for sturdy strollers, but the final climb is not.
Frequently asked questions
How long is the Observatory Trail?
The route is about 5 km round trip from the Ming Xiaoling side and takes two to three hours, with about 200 m of ascent.
Is the trail suitable for beginners?
Yes. It is graded easy, with paved sections, steps and shade, and no exposed or technical terrain.
How do visitors reach the start?
Take Metro Line 2 to Xiamafang, then walk or use bike-share, or take a taxi from Xinjiekou for about 40 to 50 CNY.
Is the observatory always open to visitors?
Opening arrangements can change, so it is best to check current access before the trip.