Beijing

Beijing has around 150 cubic metres of water per resident a year. Chinese officials treat 500 as the threshold for extreme scarcity. For decades the city made up the difference by pumping its aquifers, and the average depth to groundwater under the plain fell from 7.24 metres in 1980 to 25.75 metres in 2015. Springs dried up and parts of the city began to sink.

On 27 December 2014, water from the Danjiangkou Reservoir in Hubei reached a basin beside the Summer Palace, having travelled 1,432 kilometres along the Central Route canal almost entirely by gravity. By the end of 2025 the route had delivered 11.57 billion cubic metres.

Close to eighty per cent of the city's supply now comes down that canal, and about a fifth of it is pumped back into the ground. The aquifer has risen for nine consecutive years, 880 springs flow again, and in 2024 the Miyun Reservoir reached its highest level on record.

In 2013 Beijing's annual mean PM2.5 was 89.5 micrograms per cubic metre and the city logged 58 heavily polluted days. What followed went after coal first. Household and industrial burning was replaced with gas and electricity, heavy industry closed or moved out, and old vehicles were scrapped in large numbers.

The annual mean first met China's national standard of 35 in 2021. In 2025 it reached 27, down just under seventy per cent on 2013, with one heavily polluted day and 311 days rated good or excellent.

The honest caveat is that 27 is still more than five times the World Health Organization's guideline. Summer ozone is now the city's main problem pollutant, and winter inversions still bring grey days. But Beijing's reputation is running about a decade behind its air, and a traveller arriving expecting 2013 will find something else.

In 2009 China's heritage and mapping agencies published the first proper survey of the Ming Great Wall: 8,851.8 kilometres, of which 6,259.6 is built wall and the rest trench and natural barrier. A later count covering every dynasty reached 21,196 kilometres across 43,721 sites.

Inside Beijing the Wall runs 520.77 kilometres in an arc through the northern mountains, with 1,510 enemy towers recorded on the Ming line. Only a handful of sections are open: Badaling, Juyongguan, Mutianyu, Huanghuacheng and Simatai among them.

The rest is closed, and that includes the stretches people most want to walk. Jiankou's crumbling crest above Xizhazi village is not open, and municipal rules prohibit organising visits to unapproved sections. In 2024 prosecutors had 1,205 online listings for wild wall trips taken down. The real threat to the unrestored wall is weather, tree roots and feet on brick that has never been repaired.