The Dannemora mine was one of the most important iron ore mines in Sweden. The mine was closed by its owners SSAB in 1992. It may have been open since the 13th century, but the first documentary reference was in 1481.
The mine supplied all the ironworks making oregrounds iron by the Walloon process (using a blast furnace and finery forge), such as Österby and Lövsta. Their products were particularly pure iron, due the manganese content of the iron ore. This made it the best material for conversion to blister steel, the main variety of steel made in Great Britain between the 1610s and the 1850s. The mine has a depth of 640 metres.
Today the area is both a historic site and mining technology museum. There are a souvenir shop, a craftshop, an atique store and a mineral museum. Visitors may stroll along the various open cast mines, the pits have vertical walls and look pretty impressive. There are some 50 open cast mines, fantastic abysses made the mine field a popular attraction for painters, writers and royalty from many countries during the 19th century. Carl von Linné visited the mines, and there are numerous historic paintings, in oil and copper engravings.
Storrymmningen is the longest open cast mine in th field, more than 200m long and 100m deep. It is visited on guided tours, which then enter the underground mine and show the main shaft going down to the 620m level. The tour ends at a small mchine house nearby, which contains the first steam engine of Sweden, which was used between 1728 and 1735 to power the water pumps of the mine.References:
Roman Walls of Lugo are an exceptional architectural, archaeological and constructive legacy of Roman engineering, dating from the 3rd and 4th centuries AD. The Walls are built of internal and external stone facings of slate with some granite, with a core filling of a conglomerate of slate slabs and worked stone pieces from Roman buildings, interlocked with lime mortar.
Their total length of 2117 m in the shape of an oblong rectangle occupies an area of 1.68 ha. Their height varies between 8 and 10 m, with a width of 4.2 m, reaching 7 m in some specific points. The walls still contain 85 external towers, 10 gates (five of which are original and five that were opened in modern times), four staircases and two ramps providing access to the walkway along the top of the walls, one of which is internal and the other external. Each tower contained access stairs leading from the intervallum to the wall walk of town wall, of which a total of 21 have been discovered to date.
The defences of Lugo are the most complete and best preserved example of Roman military architecture in the Western Roman Empire.
Despite the renovation work carried out, the walls conserve their original layout and the construction features associated with their defensive purpose, with walls, battlements, towers, fortifications, both modern and original gates and stairways, and a moat.
Since they were built, the walls have defined the layout and growth of the city, which was declared a Historical-Artistic Ensemble in 1973, forming a part of it and becoming an emblematic structure that can be freely accessed to walk along. The local inhabitants and visitors alike have used them as an area for enjoyment and as a part of urban life for centuries.
The fortifications were added to UNESCO"s World Heritage List in late 2000 and are a popular tourist attraction.