Læsø is the largest island in Kattegat, some 20 kilometres east of Frederikhavn on the Jutland peninsular in Denmark, roughly half way to Gothenburg in Sweden. It measures roughly 120km² and has population of around 2000 inhabitants. Along with the Island Anholt to the south, it's part of the Danish "desert belt" which sees substantially less rainfall than the rest of the country during the summer months, and streams and ponds have a tendency to dry up during these months.
The most common way to reach the island is by ferry from Frederikshavn, which usually sees 4-5 departures a day, and takes approximately 90 minutes. But the islands airfield also sees scheduled taxi flights from Roskilde airport, near Copenhagen, although for any budget traveller these flights tend to be prohibitably expensive; but varying slightly depending on the season, and when you book.
While there is a free scheduled bus (line 840, connects with ferry arrivals) that runs across the island from the western port; Vesterby to the eastern village; Østerby, and a cheap 4 hour guided roundtrip of the island, probably the best way to see the island is by bike, which can either be brought on the ferry, or rented on the island. Finally a more exotic way is to see the island by horseback (more details in the Do section)