The Caves of Hotton are speleothem caves located in Wallonia near Hotton in Belgium, which were discovered in 1958 and are around 5 or 6 km long and 70 metres deep. A stream called Syphon runs at the bottom of the caves.
Wikipedia https://en.wikipedia.org/wiki/Caves_of_Hotton
Official Website http://www.grottesdehotton.be/
Address 1 Spéléo-Club de Belgique, 6990, Belgium
Coordinates 50°15'33.211" N 5°27'21.123" E
