Hafnarfjörður (ˈhapnarˌfjœrðʏr̥), officially Hafnarfjarðarkaupstaður (ˈhapnarˌfjarðarˌkhœipˌstaːðʏr̥), is a port town and municipality in Iceland, located about south of Reykjavík. The municipality consists of two non-contiguous areas in the Capital Region, on the southwest coast of the country. At about 30,000 inhabitants, Hafnarfjörður is the third-most populous city in Iceland after Reykjavík and Kópavogur. It has established local industry and a variety of urban activities, with annual festival events. The town is the site of an annual Viking festival, where Viking culture enthusiasts from around the world display reconstructions of Viking garb, handicraft, sword-fighting and longbow shooting. It takes place in June each summer. Just two kilometres () outside of Hafnarfjörður is an aluminium smelter, run by Alcan. The smelter was originally built in 1969, and it has improved its cleaning process since then, especially regarding fluoride. Local elections were held in May 2006, where the people of the town voted against extension of the smelter. Hafnarfjörður takes its name (meaning harbour fjord) from the area's natural harbour. The town is built on top of Holocene lava fields erupted from the nearby Krýsuvík volcanic system, including the 8000-year-old Búrfellshraun and the much younger 2000-year-old Óbrinnishólabruni. There have been no new lava flows on the site since before the Settlement of Iceland, but the Krýsuvík system is still an active volcano, last erupting in 2021 at Fagradalsfjall further to the southwest. Hafnarfjörður is first named in the medieval Landnámabók, and the earliest reports of voyages to Hafnarfjörður date from the end of the 14th century. Englishmen began trading in Hafnarfjörður in the 15th century, but German merchants followed in their wake and eventually drove the English out. In German documents, Hafnarfjörður was mentioned for the first time in 1391, and in another German document dating from 1486 the place was described as a trading place of merchants from Hamburg for the first time.