The name of the village of Kelmis is derived from the zinc ore calamine, which was known as kelme in the region. It was mined there from the early Middle Ages until the end of the 19th century. The village became known internationally in the period from 1816 to 1919. The genesis of the neutral condominium of Moresnet goes back to a conflict between the United Kingdom of the Netherlands and Prussia in determining new borders following the demise of the French Empire. A local coin was minted under the name 'Free Community of Moresnet', but it never went into circulation in the neutral zone. In 1886, eight postage stamps were issued too, with the idea of founding an autonomous local postal service. But they were only on sale for a fortnight, as the postal service was a state monopoly.
Numerous historical relics enable visitors to immerse themselves in the enigmatic past of Kelmis. That history is explained in a clear and interesting way on the history trail, the industrial educational trail, in the Altenberg conservation area, and on information boards not far from the historical zinc mines.
