Caves of Hotton
The Caves of Hotton are speleothem caves 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.
Coordinates: 50°15′33″N 5°27′21″E / 50.2592°N 5.4559°E
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