From where I'm standing, the city-sized Baogang Steel and Rare Earth complex dominates the horizon, its endless cooling towers and chimneys reaching up into grey, washed-out sky. Between it and me, stretching into the distance, lies an artificial lake filled with a black, barely-liquid, toxic sludge.

Dozens of pipes line the shore, churning out a torrent of thick, black, chemical waste from the refineries that surround the lake. The smell of sulphur and the roar of the pipes invades my senses. It feels like hell on Earth.

Welcome to Baotou, the largest industrial city in Inner Mongolia. I'm here with a group of architects and designers called the Unknown Fields Division, and this is the final stop on a three-week-long journey up the global supply chain, tracing back the route consumer goods take from China to our shops and homes, via container ships and factories.

You may not have heard of Baotou, but the mines and factories here help to keep our modern lives ticking. It is one of the world’s biggest suppliers of “rare earth” minerals. These elements can be found in everything from magnets in wind turbines and electric car motors, to the electronic guts of smartphones and flatscreen TVs. In 2009 China produced 95% of the world's supply of these elements, and it's estimated that the Bayan Obo mines just north of Baotou contain 70% of the world's reserves. But, as we would discover, at what cost?

Element of success

Rare earth minerals have played a key role in the transformation and explosive growth of China's world-beating economy over the last few decades. It's clear from visiting Baotou that it's had a huge, transformative impact on the city too. As the centre of this 21st Century gold-rush, Baotou feels very much like a frontier town.