A shaft drilled for the construction of the First Canal. The shaft was drilled straight down from the mountain top to the depth where the tunnel was planned to be built. so that the tunnel was dug simultaneously from both outside and inside the mountain. This technology to shorten the construction time was adapted for the first time in Japan for the Lake Biwa Canal construction. While on the Lake Biwa Canal Cruise, you can see the inside of the shaft as you pass under the shaft. You can experience the groundwater spilling from the inside wall of the shaft splashing on to the boat roof.