Eighteen thousand years ago Vendsyssel lay entirely under ice. When the glaciers withdrew, the crust they had been pressing down began to rebound, and it rose faster than the melting ice could raise the sea. In the Stone Age the water stood roughly thirteen metres above its present level, so the cliffs it cut are stranded well inland — old shorelines with no shore, running through farmland. The southern part of the district is a wide plain laid down by that ancient sea, interrupted here and there by isolated moraine hills that were once islands in it. Down the middle runs the Jyske Ås, an end moraine pushed up by the ice. Around 3,000 square kilometres in all, between the Skagerrak on one side and the Kattegat on the other — and the rebound has not stopped.

At the very tip, past Skagen, the land narrows to a spit of sand called Grenen, and this is where the Skagerrak meets the Kattegat. It is not a subtle meeting: two current systems collide head-on, visible from the beach as a seam of broken water running out from the point. The reef beneath it is still building: over the last century Grenen has grown about a kilometre north-east toward Sweden, roughly ten metres a year, so the northernmost point of Denmark keeps moving. People wade out to stand with a foot in each sea. Nobody swims — the currents there can kill, and swimming is prohibited.

Vendsyssel's other great story is what the wind does with all that sand. Råbjerg Mile, on the Skagen headland, is a migrating dune covering some two square kilometres and standing forty metres high — four million cubic metres of sand that formed more than three hundred years ago and has been walking north-east ever since at up to eighteen metres a year, leaving a damp flat behind it as it goes. Historically this was catastrophe rather than spectacle. Drifting sand buried farms and fields across western Vendsyssel, and dunes could travel kilometres inland; prohibitions achieved nothing until an ordinance of 1792 shifted the strategy from banning things to planting marram grass. The most dramatic casualty is still standing, barely. Rubjerg Knude lighthouse was first lit on 27 December 1900 and switched off on 1 August 1968, beaten by sand and by a coast eroding about a metre and a half a year. On 22 October 2019 the 23-metre, 720-tonne tower was rolled 70 metres inland on rails, which should keep it out of the sea until roughly 2060.

The name is old and disputed. Adam of Bremen called the place Wendila around 1075, Ælnoth wrote Wendel around 1100, and by about 1231 the Danish census book has Wændlesysæl — a syssel being an early administrative district. Some historians and linguists trace the root to the Germanic tribe of the Vandals; others to a word meaning to turn, which may first have described the winding Limfjord rather than the land beside it. The people here are still vendelboer. What followed is a run of bad centuries. In 1085 Canute the Holy raised an army for England and never sailed, then withdrew to his royal estate at Børglum here in Vendsyssel; the revolt that broke out against him ended with the king cut down at the altar of a church in Odense in 1086. During the Count's Feud, peasants under Skipper Clement burned the bishop's stronghold at Voergaard in 1534, were crushed by the nobility, and lost their leader to the axe at Viborg in 1536 — after which almost every free peasant here lost his land. In the 1640s a Swedish army under Wrangel crossed the frozen Limfjord and met the local peasant levy at Nørresundby; six to seven hundred were killed, and roughly ninety-five per cent of that army did not come home.

For a place that looks like a dead end on the map, Vendsyssel is unusually busy, because traffic between the European continent and Norway or western Sweden funnels through it. The E39 and E45 cross it as motorways. Ferries run from Hirtshals to Kristiansand, Larvik, Stavanger, Bergen, Oslo and Langesund, and from Frederikshavn to Gothenburg and Oslo, some carrying rail freight wagons. Hourly trains work the line from Skagen through Frederikshavn, Hjørring and Brønderslev to Aalborg. The habit is old: coastal Vendsyssel traded directly with Norway from the Viking Age onward, and the skudehandel of the seventeenth and eighteenth centuries thrived partly because it slipped around various taxes. Jacob Sewerin of Sæby held the Greenland trade monopoly from 1733 to 1753 and built a winter harbour for his ships at Hals. The Vendsysselbanen railway opened in 1871, and industry followed it north. The largest towns today are Hjørring, Frederikshavn, Brønderslev, Sæby, Hirtshals, Løkken and, out at the point, Skagen — though the real centre of gravity is Aalborg, sitting mostly on the wrong side of the fjord with Nørresundby as its northern half.