The 19-Lachter-Gallery is one of the sites of silver mining that form the Rammelsberg Mine, Old Town of Goslar and Upper Harz Water Management World Heritage Site. It is a gallery 8.8 kilometres long to ventilate mines and take away water. The name ‘19-Lachter’ comes from a traditional measure of depth – the gallery was 19 ‘lachter’ (36 metres) below another tunnel. Work began in 1551 but was slow as the gallery was dug by hand through hard rock. It was completed in 1690. Visitors can explore 0.5 kilometres of the gallery and see its formation in rock or construction with stonework, wood or iron. The first part leads to a shaft 261 metres deep. A waterwheel of 9 metres diameter is demonstrated for visitors. A staircase takes visitors down 100 metres below the surface to a water turbine and a compressor installed in 1914.