On November 13, 1872 Lolland, Falster and also Nakskov Fjord experienced Denmark's greatest natural disaster. Colloquially called the ’Storm flood’. At the peak of the flood, water levels reached an average height of 3.5 metres over the usual high water level at South Lolland’s coast. About 80 people drowned on Lolland and Falster, several thousand livestock disappeared in floodwaters, and over 500 ships were wrecked.
The scale of the disaster triggered a large-scale dike construction, and within a few years dikes were built almost all the way from Nysted to Albuen. In Nakskov Fjord the dikes were erected from island to island, making the islands part of the dike. Especially the south side of Nakskov Fjord was totally changed. The islands Ydø, Langø, Bogø, Bondeholm, Store Vejlø, Lille Vejlø, Stensholm, Stensø, Færgelandet, Mellemlandet and Stubbelandet became forever part of Lolland. The islands are named as they were found, coming from the west.
The area is called The Lost Archipelago. It can be hard to discern the old islands in the landscape, as many of these were quite low with flat shores, but see the map where the main roads and towns are marked, and you can go exploring in The Lost Archipelago.
A single dike cuts across the archipelago at Langø road. It is a so-called box dyke, of which there are six; these go across country, dividing the hinterland into five boxes. Should the dike breach, only one boxed area will flood, not the whole hinterland.