How does the human brain allow us to interact with and navigate through a constantly changing world? Whilst controlled experiments using functional brain imaging can give insightful snapshots of neuronal responses to relatively simplified stimuli, they cannot hope to mirror the challenges faced by the brain in the real world. However, trying to study the brain mechanisms supporting daily living represents a huge challenge. By combining functional neuroimaging, an accurate interactive virtual simulation of a bustling central London (UK), and a novel means of 'reading' participants' thoughts whilst they moved around the city, we ascertained the online neural correlates underpinning navigation in this real-world context. A complex choreography of neural dynamics was revealed comprising focal and distributed, transient and sustained brain activity. Our results provide new insights into the specific roles of individual brain areas, in particular the hippocampus, retrosplenial, and frontal cortices, as well as offering clues about how functional specialisations operate within dynamic brain systems.