Blue Hole - Taroko There are a series of awesome tunnels in Taroko Gorge, some close to 1/2 a mile long. I laughed at Arianna when she suggested we bring a flashlight, but as we hiked into the near-total darkness I was quite greatful. This is at the exit to one of those tunnels - the left side of the frame is the tunnel wall and the right side is the canyon wall. They are really several hundred feet apart in actual distance, hence the grass on the left is larger than the full trees on the right.