During a one-way trip from Trondheim to Frøya, one drives through 10 tunnels. Some are a relatively modest 600 meters, others are 10 times that long and take 5 or 10 minutes to traverse. The two longest of these tunnels go underneath fjords. Norwegians have perfected tunneling technology, and can build them for 1/5 the cost of tunnels in the US. Norway has now surpassed Switzerland to become the tunneliest country in the world. (Is "tunneliest" a word? It should be.)
Here's a psychodelic tunnel trip. Enjoy!