Rjukan

In 1906 the land that became Rjukan was a handful of farmsteads called Saaheim, when Norsk Hydro began planning fertiliser production in the valley with the new Birkeland–Eyde process, which fixed nitrogen from the air using electricity. The company bought the Rjukan Falls, harnessed in 1905, and built the Vemork power station in 1907–1911, then the largest hydro-electric plant in the world. Factories, workers' houses, a station and a town hall followed, the Rjukan Line carried chemicals down the valley to the train ferry on Lake Tinnsjø, and by 1920 the new town had about 8,350 people.

In 1934 Norsk Hydro added a hydrogen plant at Vemork, and its by-product, heavy water, made the site the only regular producer in Europe — and, once Germany occupied Norway in 1940, a target. The Allied operations Grouse, Freshman and Gunnerside, with Norwegian commandos dropped onto the Hardanger Plateau, knocked the plant out of production in early 1943, and in 1944 a ferry carrying heavy water was sunk on Tinnsjø.

After 1960 most of the fertiliser production moved to Herøya in Porsgrunn, and the town shrank. Tinn's council gave Rjukan town status in 1996. On 5 July 2015 the industrial landscape became part of the Rjukan–Notodden Industrial Heritage Site on UNESCO's World Heritage list. Two years earlier the town had finally realised an idea first proposed by Norsk Hydro's founder Sam Eyde about a century before: mirrors on the mountainside that reflect the winter sun onto the square.

Rjukan is a company town in its bones. Norsk Hydro built not only the plants but the houses, the institutions and the social life of the valley, and the World Heritage listing recognises the workers' housing and social buildings as much as the turbines. The Norwegian Industrial Workers Museum at Vemork, founded in 1988, tells that story alongside the wartime sabotage, which is a central part of local identity.

Light is the other theme. Gaustatoppen blocks the low sun for roughly half the year, so Norsk Hydro built the Krossobanen cable car in 1928 to carry workers up into the winter sun, and since 2013 the sun mirrors have lit part of the town square. Solfesten celebrates the sun's return around 12 March, when it reaches the factory bridge again.

The valley has drawn travellers for two centuries. In 1811 a royal geologist reported the Rjukan Falls to the king as the tallest waterfall in the world — wrongly — and the falls became a famous sight for the European upper classes; a local resistance veteran later called Rjukan "the cradle of tourism in Norway". Today the town is known among climbers as one of the best ice-climbing areas in Northern Europe, celebrated with an ice festival since 1995, and the Gaustablikk ski area is one of the largest in Norway.

About 3,000 people live in the town (2025), far fewer than the more than 12,000 of its industrial peak. It is the administrative centre of Tinn Municipality, and the long, narrow town follows the valley floor between the lakes Møsvatn and Tinnsjå; its main street, Sam Eydes gate, is 7 km long.

The large fertiliser works left after 1960, and tourism has become a mainstay alongside the municipal administration. Visitors come for the museum at Vemork, for Gaustatoppen and the Hardangervidda plateau in summer, and for skiing at Gaustablikk and ice climbing on the frozen waterfalls in winter.

The year is set by the light. From autumn to March the valley floor lies in the mountain's shadow, and people ride Krossobanen or drive up to the slopes to see the sun, or stand in the patch of reflected light on the square. Spring brings Solfesten, summer the walkers and hikers, and winter the skiers and ice climbers.

Traditional Norwegian country food is the background here. Older dishes include fårikål, the mutton and cabbage stew counted as the national dish; rakfisk, trout salted and fermented for months and eaten without further cooking; flatbrød and lefse, a soft flatbread made with potato, milk or cream and flour; and rømmegrøt, a porridge in which the milk is replaced with sour cream.

Goat cheese made in the traditional way in the surrounding mountains is the local speciality to buy, and brunost, the sweet brown cheese of caramelised lactose from goat's milk or a mix of goat's and cow's milk, is popular with bread. Lapskaus, a stew of meat with potatoes, carrots, swede and onion, is everyday home cooking across Norway.

The town's restaurants, cafés and pub are small and gathered in the centre, and many visitors self-cater in cabins. Beer under 4.75 per cent is sold in supermarkets, while wine and spirits come from the state Vinmonopolet shops. The oddest local purchase is not food at all: tiny ampoules of real heavy water, sold as souvenirs at the museum and the tourist office.