Lucerne, Switzerland: Needle Dam

Sometimes the old ways still work out just fine. Such is the case with the Needle Dam.

This was designed to keep the water level of Lake Lucerne at a manageable level. It is done manually, to keep water levels at the right height year round. The rest drains down the Reuss and eventually goes into the Rhine. Some work around 2010 allows the engineers to drain about a third more water than under the old setup, so bottlenecks won't develop so easily.

It doesn't exactly look sturdy, but it works.