This lake is the third largest in Sweden and occupies an area of 1,140 square meters. On its islands Viking artefacts have been found making this a world heritage site. Although you can access the lake from different city and towns, even from Stockholm, we visited from Vasteras. It is highly recommended to sail on it on typical boats leaving at sunset which offer dinner on board. Seeing the colors of the sunset on this lake is an unforgettable experience. Curiously, this lake also boasts the world's only underwater hotel, located just a few miles from the coast of Vasteras. There is just a room but it has great detail.