Two years later the land went to a plantation owner named Lassen, recently home from Brazil, who bought it and planted it with trees. In 1901 he handed the whole site to Nørresundby Municipality, and it has been public ground ever since; the state formally protected it in 1960. What Lassen owned briefly and gave away turned out to hold more than 700 graves and several hundred stone ship settings — the largest assemblage of well-preserved examples anywhere. The oldest burials date to around the year 500, in the Nordic Iron Age. The newest belong to about 1100, at the close of the Viking Age. Six centuries of one community's dead lie on a single slope, forty-two metres above the water, in full view of the fjord that gave the place its reason to exist.

Most of the people here were cremated; a smaller number were laid in the ground unburned, and the balance shifted over time, with cremation displacing inhumation as the Viking Age arrived. The earlier burials went under mounds. The later ones were outlined in fieldstone — some women's graves ringed in circles or ovals, a few in triangles, but most in the long tapering shape of a boat. The size and form of the outline appear to record the standing of the person inside, the same logic that governed ship burials among the Anglo-Saxons and the Norwegian and Swedish Vikings. Walking the hill, you never actually see a ship. You see stones in wet grass, and your eye does the rest, assembling prow and stern out of nothing. It is a fleet drawn in rock, pointed at a fjord, and not one of these vessels ever took on water.

The Limfjord is at its narrowest right here, which is the whole answer. This was the crossing between Vendsyssel and the rest of Jutland, and during the Viking Age it was one of only two places you could realistically get across — the other lay far to the west at Aggersund — because swamps edged the water almost everywhere else. Excavations turned up the remains of a village alongside the graves. The finds argue for something busier than a farming hamlet: glassware, gems, Arab coins, and an eleventh-century silver brooch in the Urnes style. People who lived at a chokepoint on a trade route were buried where they had made their living, on the rise overlooking the ferry.

Toward the end of the Viking Age, drifting sand covered the entire area. Heavy deforestation along the North Sea coast had loosened the dunes, and the rough westerlies carried them inland year after year until fields and houses went under. The settlement was abandoned around 1200. What ruined the place is exactly what saved it — the sand sealed the burial ground and kept it, more or less intact, through eight centuries in which almost nothing was built on top of it. The site's worst losses came later and from human hands: an unknown number of the marker stones were carted off over the centuries, many broken up in the nineteenth century for road building. The Viking Age section suffered that plundering far worse than the older ground uphill.

Digging had begun as early as 1889, but the campaign that revealed Lindholm Høje ran from 1952 to 1958 under the chief archaeologist Oscar Marceen, and it was an earth-moving operation as much as an archaeological one. Fifteen to twenty labourers worked the site, and a narrow-gauge tipper railway was laid to haul the excavated sand over to the north side of the hills. In the end 589 of the roughly 700 graves were opened. A museum went up beside the site in 1992, financed by the cement company Aalborg Portland to mark its centenary; it became part of Nordjyllands Historiske Museum in 2004 and was enlarged in 2008 with support from the A.P. Møller Foundation, adding an exhibition on the prehistory of the Limfjord. For twenty summers, from 1993 to 2012, an open-air play was staged on the hill each June — a crowd sitting among the stone ships, watching something staged where the real thing had already happened.