The Battery sits at Manhattan's southern tip, where New York began as a Dutch trading post in 1625. Most of the park didn't exist back then. It's built almost entirely on landfill, earth and rubble hauled in over centuries to push the city further into the harbour. Where families now picnic and tourists queue for ferry tickets, there was once only water lapping at the walls of Fort Amsterdam.

The park takes its name from the artillery battery that defended the harbour in the 1700s. Alexander Hamilton led a daring raid here in 1776, seizing British cannons under cover of darkness and dragging them back to American lines. Castle Clinton, the circular sandstone fort at the park's heart, arrived later in 1811, built on its own island until more landfill swallowed the water around it.

By the 1990s, the park had become what The New York Times called a wreck: broken benches, dirt where grass should be, graffiti obscuring the signs. Hurricane Sandy's 14-foot storm surge in 2012 submerged it entirely. The restoration that followed made it both prettier and tougher.

VoiceMap's self-guided audio tours use the Battery to trace New York's origins, following the waterline back through Dutch deals and British occupations, explaining how a city built itself outward on its own demolished hills.