I've been to round trip back to Tokyo by taking different route between to and from Tokyo.On the way to Tokyo,my wife and I stayed at the hot-spring hotel in Nagano located near the lake.Along the lake there was a periodic spring,that we call Kanketsu-sen,where onsen hot water shoot the air to nearly five or six meters high with very punctual timing every two hours!It was spectacular to watch and also the wonder of nature why so periodically it springs as if the earth is a living creature and has its biological clock inside.