Needle Dam 

From the Spreuer Bridge, there is a fascinating view upstream: the Needle Dam (also known as the Reuss Weir). Built between 1859 and 1861, the weir is a historical monument and marvel of 19th century engineering.

The water level of Lake Lucerne is still regulated manually by the removal or insertion of timber «needles». This regulation – to prevent flooding, for instance – allows the level of the lake to be kept at a height to suit the seasons, regardless of the weather.

The weir was renovated and extended between 2009 and 2011. Now a third more water can be drained from the lake at high tide. That's around 430 cubic meters of water per second.