In the early 1990s, from an aircraft descending into Beijing, I looked down upon a landscape of heavy industry stretching along a mountain-lined valley. I saw giant cooling towers, tall chimneys belching out smoke, railway tracks lined with trains hauling mineral wagons. It was not quite the scene I was expecting, having visited the city initially in 1987. I recalled grand imperial palaces, boating on tranquil lakes to a background of forested hills, of quiet old lanes. Yet, heavy industry was not an image I had retained or indeed perceived. Interestingly I found no mention of this in my guidebooks or city maps that mainly concentrated on principal tourist sites.

The following year, 1995, I traveled to Pinguoyuan, the last stop on the east-west metro line 1. It was where buses connected with my intended destination, the beautiful Fragrant Hills. Walking towards a transfer stop I saw again cooling towers. There was a hint in the air of coal burning, of industrial gases, and visibility not as clear as downtown that day.