Goslar, Germany: UNESCO imperial town, medieval old town and the thousand-year Rammelsberg mine

Goslar owes its existence to silver. After rich ore veins came to light in the Rammelsberg hill, a settlement was founded at its foot in 922, and within a century the town had become a favourite residence of the Holy Roman emperors - so grand that an eleventh-century chronicler called its palace the most famous residence in the empire. This town of around 50,000 people lies at the northern foot of the Harz in Lower Saxony, about 40 kilometres south of Braunschweig and some 70 kilometres south-east of the state capital, Hanover.

The Kaiserpfalz, the restored Romanesque Imperial Palace, still dominates the southern edge of the old town, its great Imperial Hall among the largest secular spaces to survive from the Middle Ages. Below it spreads a market square ringed by the medieval town hall, the gabled Kaiserworth guild house and the market church of Sts. Cosmas and Damian.

Emperors, ore and the Hanseatic League

Imperial assemblies met here repeatedly in the eleventh and twelfth centuries, and Goslar later joined the Hanseatic League, drawing its wealth from the Rammelsberg metal ores. It kept the rank of free imperial city until Prussia annexed it in 1802. The mine itself is extraordinary: worked without interruption for more than a thousand years before it finally closed in 1988, it ranks among the largest non-ferrous mining complexes in Europe.

A World Heritage triple

UNESCO inscribed the historic old town and the Rammelsberg mine in 1992, and in 2010 extended the listing to the Upper Harz Water Management System, an ingenious medieval web of ponds and ditches that powered the workings. Around 1,500 timber-framed houses fill the lanes, and each year the town awards the Kaiserring, an art prize sometimes called the "Nobel Prize" of the art world. Spared wartime bombing, Goslar remains one of the best-preserved medieval centres in Europe.