The main objective of the circulatory system is  transporting oxygenated (rich saturation of oxygen) blood around  the body. The de-oxygenated blood enters through the vena cava and  into the right atrium of the heart. It then goes to the right  ventricle, directly below the atrium.
Pyramid of the Sun. Less than half a mile south of the Pyramid of the Moon is the Pyramid of Sun. At a height of more than 200 feet (63 meters) and a base more than 730 feet (225 meters) long on each side, this pyramid is one of the largest structures created in the pre-Columbian New World. It would have been completed around 200 AD.
1 Khufuâs pyramid, known as the great pyramid of Giza, is the oldest and largest, rising at 481 feet (146 meters). 2  Archaeologists say it was the tallest structure in the world for about 3, 800 years. 3  The relationship between Pi (p) and Phi (F) is expressed in the fundamental proportions of the Great Pyramid. The Pyramid of Menkaure, the Pyramid of Khafre and the Great Pyramid of Khufu are precisely aligned with the Constellation of Orion. 2  The base of the pyramid covers 55,000 m2 (592,000 ft 2) with each side greater than 20,000 m2 (218,000 ft2) in area.