Work on driving this tunnel began in 1738, at the same time as construction of the Richňava tajch (a historic mining reservoir).
The tunnel was surveyed and designed by Samuel Mikovíni. It was driven from both ends at once and broke through in 1742, about two years after the tajch was completed, while the reservoir was filling with water. The tunnel is 920 m long.
Its purpose was to carry water from tajch Richňava to the Siglisberg feeder channel, whose water was used to power mining and ore-processing machinery and also to top up the lower-lying tajchs Veľká Vindšachta and Evička.
The tunnel’s sluice gate was reached by a small shaft fitted with ladders and resting platforms. The shaft was driven from the water tunnel all the way up to the surface and had a vertical height of about 25 m. A New Richňava Water Tunnel was also built in the second half of the 18th century.
