Above the south porch of St Andrew's, cut into the flint, is a Saxon sundial: a semicircular head with thirteen time-lines, cross marks and the inscription "+EAD RIC". It has kept the hours here since Saxon times. The parish dates the building to somewhere between AD 600 and 800 and calls it an Anglo-Saxon minster, the last visible remnant of a high-status settlement dug up between 2002 and 2005.
The church stands where the village is: among flint walls, fields and chalk slopes in the Bishopstone valley, a mile or so inland from the coast. This is not the seaside end of Seaford that shares the name. It is a small downland settlement, quiet, with a village green officially recorded as especially tranquil, which is the sort of thing that only gets written down when someone worries it might be lost.
St Andrew's rewards a slow look. The nave and porch are Saxon, the north aisle and east end Norman, the tower a mixture of the two. Inside there is a twelfth-century font, a medieval coffin lid, an eleventh-century north window, an aumbry and piscina, a fragment of wall painting, and bells hung in 1761. Historic England grades it I, dating it more cautiously than the parish: a building mainly Norman to Early English, with Saxon work surviving in the porch and tower.
They were not the first. Excavation at Rookery Hill in 1971 turned up occupation running from the Neolithic through an Iron Age enclosure and Romano-British farmyards to an Anglo-Saxon building. By 1086 Bishopstone was substantial: 52 households, 30 villagers and 22 smallholders, forty acres of meadow, and a value of £25 10s, held by the Bishop of Chichester. It sat in the largest fifth of settlements the Domesday surveyors bothered to record.
The reason to walk out of the village, though, lies south, where the River Ouse winds between the downs toward Newhaven. A five-mile circular from the village crosses the Ouse Estuary Nature Reserve and reaches Tide Mills, and it is an easy route with a few stiles and one long, gentle hill. The reserve is wet ground, shingle, grazing fields and flood storage, with more than a hundred bird species recorded; teal, moorhen, shelduck and mallard are the ones you are most likely to name. A surfaced path leads to a bird screen and is level enough for a wheelchair or a buggy, and there are wooden sculptures by Steve Geliot along the way. Cattle graze much of it from April to October.
Tide Mills itself is a deserted village. Three West Sussex corn merchants dammed a former channel of the Ouse in 1761 and built a tidal mill; a railway arrived in 1864, the mill closed in 1883, and the settlement clung on until it was evacuated in wartime by 1941. Its later lives are hard to summarise: a wireless relay station, a 1917 seaplane base, Captain David Dale's racing stables, a children's hospital, and a sunken manure-heated pit in which the mill owner William Catt grew pineapples, one of the earliest such pits ever excavated. What remains now is concrete track, fragments of wall and interpretation panels on the way down to a shingle beach. "But we're still finding buildings we didn't know about," says Luke Barber, the Sussex Archaeological Society research officer.
Bishopstone has its own station on the coast road, step-free to every platform, though with no station car park and nothing to eat there. Its octagonal booking hall of 1936 copies Charles Holden's Underground stations, and two pillboxes were dug in beside it in 1940. On 3 July that year an enemy aircraft machine-gunned the 17:37 from Seaford between here and Tide Mills, killing the driver, Charles Pattenden.
For a pub and a proper meal you head out along the coast, to Seven Sisters and the Cuckmere valley, where the Cuckmere Inn at Exceat serves home-baked pies and welcomes dogs on leads in the bar and garden; Seaford, a mile and a half off, is the nearest place for shops. But the village keeps its best thing to itself. Stand under the porch on a clear afternoon and the sundial is still doing its job, marking the hours much as it always has.