The bay is a huge, shallow, salty inlet of the Indian Ocean, and it holds the largest seagrass meadows in the world, which feed a population of dugongs, turtles and dolphins. The water is clear, the sand is white and the cliffs are red.
Several remarkable things sit in a short distance. At Monkey Mia, a beach not far from Denham, wild bottlenose dolphins swim into the shallows each morning to be fed by rangers, a tradition that began informally decades ago and now follows strict rules. At Hamelin Pool, the water is twice as salty as the sea, and it hosts stromatolites, rounded mounds built by microbes, which are living relatives of some of the oldest life forms on Earth. At Shell Beach, the sand is made up of billions of tiny white cockle shells, stacked metres deep for many kilometres.
The history is old and thin. In 1616 the Dutch captain Dirk Hartog landed on an island at the mouth of the bay and nailed a pewter plate to a post, the first recorded European landing on the Australian coast, and the island now carries his name. Pearling, fishing and salt have kept the area alive since. The Francois Peron National Park, on the peninsula north of Denham, has red dunes, white beaches and blue water, though much of it needs a four-wheel drive to explore.
For the rider, the road to Denham is a long spur of more than a hundred kilometres off the North West Coastal Highway, running through low scrub and past salt pans, and it ends at the sea. Distances between fuel stops are long, so Denham has a station and basic supplies, and it is wise to fill up there. Wind is often strong, and the heat is fierce in summer.
Pack plenty of water, sunscreen and a hat. A swim in the clear water, a plate of fresh fish and an evening on the jetty, watching the sky turn pink, will reward the long road.