Its northern part is actually insular, divided from the mainland by the Limfjord or Liimfjord, which communicates with the North Sea to the west and the Cattegat to the east, but this strait, though broad and possessing lacustrine characteristics to the west, has only very narrow entrances.
This would point to the fact that the Limfjord was then open at both ends, and agree with Adam of Bremen (iv.
AALBORG, a city and seaport of Denmark, the seat of a bishop, and chief town of the amt (county) of its name, on the south bank of the Limfjord, which connects the North Sea and the Cattegat.
To the west the Limfjord broadens into an irregular lake, with low, marshy shores and many islands.
Towards the north a narrow mouth gives entry to the Limfjord, or Liimfjord, which, wide and ramifying among islands to the west, narrows the east and pierces through to the Cattegat, thus isolating the counties of Hjorring and Thisted (known together as Vendsyssel).
The Varde, Omme, Skjerne, Stor and Karup, sluggish and tortuous streams draining into the western lagoons, rise in and flow through marshes, while the eastern Limfjord is flanked by the swamps known as Vildmose.
The eastern touches the ports of Kolding, Fredericia, Vejle, Horsens, Aarhus, Randers, Aalborg on Limfjord, Frederikshavn and Skagen.
Both throw off many branches and are connected by lines east and west between Kolding and Esbjerg, Skanderborg and Skjerne, Langaa and Struer on Limfjord via Viborg.
As Ptolemy seems to have regarded the district north of the Liimfjord (Limfjord) as a group of islands, the territory of the Cimbri, the northernmost tribe of the peninsula, would be included in the modern county (Amt) of Aalborg.
The entrances to the inner lagoons of the Limfjord are naturally blocked against the immigration of flatfish by dense growths of sea-grass (Zostera), although the outer lagoons are annually invaded by large numbers of small plaice from the North Sea.