Læsø is a Danish island that lies in the stretch of water called Kattegat, off the eastern coast of northern Jutland. It began to emerge from the sea just 4-5000 years ago, and remains very flat. The southernmost part still rises at a rate of around 5 mm a year. Like most parts of Denmark, its landscape has been shaped by the presence of humans, to the extent that its diverse natural areas - saltmarshes, mudflats, heathland - are threatened by vegetational succession where human cultivation declines. Its woodlands are also 'manmade', as they were replanted at the beginning of the 1900s: the island's salt production from the 12th to the 17th centuries hed required a lot of wood as fuel, leading to deforestation.