Læsø ("Isle of Hlér") is the largest island in the North Sea bay of Kattegat, and is located 19 kilometres (12 mi) off the northeast coast of the Jutland Peninsula, the Danish mainland.

[8][9] The population has been steadily declining, and according to Danmarks Statistik (Statistikbanken.dk) was: Its mayor is Karsten Nielsen as of 2021.

The nature-types on and around Læsø includes open water, extensive mudflats, sand banks, heathland, islets and areas of arable land.

It houses Denmark's largest tidal saltmarsh outside the Wadden Sea but the decline in grazing animals has led to a gradual vegetational succession.

Invasive species are colonizing the site, especially Japanese Rose, and scrub clearance has been implemented to re-establish the former pastures open heathland.

[11] Together with Anholt, Læsø belongs to the Danish "desert belt"; during the summer months there is so little rain that streams and ponds partly dry up.

The final concentration, carried out in hundreds of salt kilns, consumed large amounts of wood.

Eventually the island became deforested, sandstorms buried villages, and salt extraction was banned.