Camber Sands is defined by three things that are really one thing: the dunes, the tide, and the camera. All three exist because the beach is enormous, flat, and open, with nothing built on the sand itself.

Start with the dunes, because they are the rarest feature. Camber holds the only sand dune system in East Sussex — a genuine geological scarcity on a coast that is otherwise shingle (Dungeness, a few miles east, is one of the largest shingle expanses in Europe). The Camber dunes are wedge-shaped, roughly 1 km wide where they meet the River Rother estuary in the west and narrowing to about 10 metres wide at the Kent end, three kilometres away. They are not static. The system is accreting at around 7,500 cubic metres of sand a year, which means the dunes are physically getting bigger over time. The mechanism is a conveyor belt powered by the tide and the wind. At low water the sea pulls back almost a kilometre, exposing a huge apron of damp sand. The sun and the prevailing south-westerly wind dry the surface and then lift the loose grains and carry them landward, where marram grass — the dune-builder, with roots that bind sand and stems that survive burial — catches and anchors them. Layer by layer, year by year, the dunes climb. The western core is protected as the Camber Sands and Rye Saltings SSSI; it carries over 250 species of plants and animals, including a beetle that exists nowhere else in the county. The dunes are fragile in the way all dunes are — a single trampled path can blow out into a gap that the wind then enlarges — so management here means fencing, boardwalks, marram planting, and the annual cutting and burning of invasive sea buckthorn.

The tide is the same fact seen from the water. The gentle shelf that makes Camber feel like you can walk to the horizon at low tide is exactly what makes the incoming tide a killer. Because the beach is so flat, the rising water does not climb a slope — it floods sideways across the sand at speed, filling the runnels and channels between the sandbars. People walk a long way out at low water onto a bar that feels solid and dry, and then the tide returns behind them, drowning the channel they crossed and cutting them off on a shrinking island of sand while the water around them rises and the current runs. This is not a rip-current beach in the surf sense; at the 2016 inquest an oceanographer testified that there was insufficient wave activity to build classic rip currents, and that the men got into trouble in a fast incoming tide over the sandbar topography. Five friends — Kenugen Saththiyanathan (18) and his brother Kobikanthan (22), Nitharsan Ravi (22), Inthushan Sriskantharasa (23), and Gurushanth Srithavarajah (27), all from the London area and of Sri Lankan origin — drowned on 24 August 2016, seen earlier playing in the shallows. They were fit, competent swimmers. A month before, on 24 July 2016, two more men had died: Mohit Dupar, 36, lost his life trying to reach 19-year-old Gustavo Silva Da Cruz, a Brazilian visitor in difficulty. Coroner Alan Craze held a five-day inquest in Hastings and recorded misadventure on all seven. He found it could not be known whether lifeguards would have prevented the deaths. Camber had had none; the RNLI had recommended a lifeguard service years earlier, but it had not been funded. After 2016, Rother District Council found the money — about £51,000 for the first season — and the RNLI began a seasonal lifeguard service in 2017, with red-and-yellow flags marking the patrolled swimming area. The flags are the whole point: on a beach this flat, where to enter the water is not obvious, and the safe zone is wherever the lifeguards have decided the tide and the bars are least lethal that day.

The camera is the third face of the same flatness. A beach that is wide, level, and free of buildings is a film location that can be almost anywhere on Earth. Camber has been the Sahara: 'Follow That Camel' was shot here in 1967, and filming had to stop repeatedly because the dunes kept getting covered in snow. It has been a war coast over and over — standing in for the beaches of Dunkirk in the 1958 film 'Dunkirk', and for occupied France when 'The Monuments Men' (2014), with George Clooney and Matt Damon, came ashore. It appears in 'The Loneliness of the Long Distance Runner' (1962), in 'The Theory of Everything' (2014), and in the closing scenes of the 2016 thriller 'Criminal'. Sixty years of location managers have used the same asset: a horizon of clean sand five kilometres from the antique-shop streets of Rye, where a film crew can build a desert or an invasion and strike it again before the next tide comes in. The dunes, the deadly tide, and the desert-double all come from one geography — the sea here goes very far out, and it comes back very fast.