On my first visit to the Greenwich Foot Tunnel, I decided to stick a field recorder in my backpack and walk from the south side to the north side of the tunnel. The recording starts as I descend the stairwell in the south entrance, with a few voices and hums, builds as the tunnel reverberates the sound of people walking in both directions, along with bike chains and a busker setting up, before reducing to a calm climb of the north entrance stair well. Taking a sonic snapshot of an urban location, detaches from the initial multi-sensory experience, generating a new and ambiguous lens. Listening back conjures images of a theatre of steadily rising and falling chaos, reflections and echoes advancing and retreating in synchronicity with the activity.