 The radius of the sphere is 3.21 meters (corresponding to March 21, Spring Equinox), the cantilever length is 6.22 meters (corresponding to the summer solstice on June 22), the height of the tower is 12.22 meters (corresponding to the winter solstice on December 22), and the inclination angle of the two portal pillars corresponds to 23.50 North latitude.Every summer solstice at noon, when the sun shines directly on the Tropic of Cancer, the shadow will pass through the central tube of the upper sphere, and the sun shines directly on the center of the platform.The Turtle Lake is under the Eagle Rocky Hill.