In the thirteenth century AD, the city of Karakorum was founded as the capital of the Mongol Empire. Relatively little archaeological attention, however, has been directed at the site and the phenomenon of steppe urbanism. The authors report new magnetic and topographic surveys of the walled city and the surrounding landscape. The resulting maps reveal the city in unprecedented detail. Combining the magnetic and topographical data with aerial photographs, pedestrian surveys and documentary sources reveals the extent, layout and organisation of this extensive settlement. Road networks and areas of variable occupation density and types of activities deepen our understanding of this important commercial hub and royal palace, which is conceptualised as a form of ‘implanted’ urbanism.