The Wieliczka Saltworks Castle has been developing since the 13th century in direct vicinity of a shaft hollowed out in search of salt. It is an example of medieval defence construction, closely related to the history of the state mining enterprise, i.e. the Cracow Saltworks in Poland before the partitions. The salt mine, bringing together the salt works and salt mines in Wieliczka and Bochnia under one management, was the largest Polish enterprise and one of the largest in Europe. The castle was the seat of the management until 1945 when its central section was destroyed by bombs. After renovations, it houses the Cracow Saltworks Museum Wieliczka, conducting studies on the salt heritage on the basis of the historical book collection, the salt works archives and valuable cartographic resources of the salt works. The complex of the castle consists of three main structures: the central one, the so-called the House within the Saltworks (end of the 13th – 17th century, 20th century) housing an impressive Gothic hall with a reconstructed vault supported on a central pillar, the northern one – the Saltworks House (built between the 14th and the 15 century with the use of defence wall from the end of the 13th century, rebuilt between the 16th and the 20th century) and the southern one (1834 – 1836, 20th century). The complex also encompasses the reserve of the mining shaft from the middle of the 13th century, secured ruins of the saltworks kitchen, and fragments of defence walls with a tower. The preserved facilities of the Saltworks Castle constitute a unique complex with historical values important for world heritage, which is an interesting example of medieval development, remodelled during Renaissance, Baroque and in the modern times. The untypical character of the castle with economic and administrative functions, as well as representative, and, to a lesser degree, residential functions, provides it with a unique position. The absence of comparable complexes in Poland (with respect to scale and type) and an extended period (of several hundred years) of direct relation to an industrial enterprise distinguishes the Wieliczka facility also among few similar European complexes preserved to this day. The article analyses, in a comparative manner, the individual facilities from the area of Slovakia, Austria and France.