The city of Yellowknife has its origins in gold mining and was designated as territorial capital in 1967. With its modern amenities and small town feel, Yellowknife has a number of interesting attractions, including the Prince of Wales Northern Heritage Centre, numerous walking trails, and the northern lights (aurora borealis), which are best seen between late August and mid-April. The city hosts a number of events, including the Frostbite 45, the Diavik 150 Canadian Championship Dog Derby, and the SnowKing Winter Festival, which involves the construction of a snow castle on Great Slave Lake, where daily festivities include live music and children's programs. And every summer since 1980, Yellowknife has held Folk on the Rocks, an outdoor music festival featuring local, national and international musicians.