The Houlong Crossing Harbor Tunnel is located in Miaoli County, Taiwan. It is a monorail with a history of a hundred years. It is connected by three continuous long and short tunnels made of red bricks. It used to be an abandoned old building. Cultural units have given new life to the monuments, repaired the tunnels, and filled the tunnels with red, orange, yellow, green, blue, indigo, purple, and rainbow-like dreamy LED lights. Walking travelers walk in it as if walking on the romantic Rainbow Avenue of Stars.