The Rothschönberger Adit drainage gallery, excavated between 1844 and 1877, is the deepest and most important drainage adit in the Freiberg Mining Field. At the beginning of the 20th century, the adit was the longest underground structure in the world, at over 50 km in length. The front section of the tunnel (as far as Halsbrücke), known as the fiscal section, is 13.9 km long; the main section within the mining field is 15 km; and the branches leading to the pits are 22 km. The Rothschönberger Adit was sunk to a depth of nearly 128 m under the Tiefe Fürstenstolln adit in the Freiberg district, and gave mining in the Freiberg Mining Field a significant boost until operations temporarily ceased in 1913. To this day, it provides drainage for all mine workings above the adit for Halsbrücke, Grossschirma, Freiberg and Brand-Erbisdorf. The adit has two openings that give onto the river Triebisch. In addition to the main adit mouth, there is also a mouth for the Triebisch leat. The openings are located in the municipality of Klipphausen near the district of Rothschönberg.