On the island of Læsø, located off the coast of Denmark, there are houses with roofs made of seaweed. These roofs are up to a meter thick, and the way they hang over the walls the house appears to be wearing a cloak. Apart from their humongous size, they look a lot like thatch but seaweed is far more durable. Some of these roofs are over 300 years old. They are a unique feature of the island of Læsø.

Photo credit: Jörg-Dieter Langhans/Flickr