There is not much of a public transport system. If you came to Myvatn by bus, walking, biking and hitchhiking are you best options but beware as it can get quite chilly in the winter. The road around the lake is approx. 36km. so biking is a good option. There are some local trips available at Skútustaðir, Vogar and Reykjahlíð Ask store clerks or information centers for details