On moonlit nights, when the pier is silhouetted against the glittering water, the ghost-sounds of a Palm Court orchestra seem to lilt across the waves.

After decades of lawsuits, in 1967 the Supreme Court capped Illinois's diversion at 2.1 billion gallons (8 billion litres) of water each day.

Part of the vast central court is a turquoise reflecting pool which has no water, but is filled with frogs and graceful waterfowl.