Pier 39 sits on reclaimed landfill at the edge of San Francisco Bay, which is either a mildly unsettling geological fact or a neat metaphor for the whole enterprise. In 1978, a man named Warren Simmons looked at a workaday industrial pier and decided it should become something else entirely. The result was, at the time, a genuinely novel idea: an open-air complex of restaurants, shops and street performers with Alcatraz as its backdrop.

The most unscripted addition arrived in 1989, just before the Loma Prieta earthquake, when a handful of sea lions hauled themselves onto the K-docks and refused to leave. Their colony grew to around 900. The pier now employs a dedicated sea lion herder to discourage them from spreading to neighbouring piers.

VoiceMap's tours use Pier 39 as the starting point for a walk along Fisherman's Wharf to Ghirardelli Square, tracing the waterfront's transformation from industrial port to the city's most recognisable stretch of coastline.