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.
Khufuâs son, Khafre (also known as Chephren). His pyramid, on a nearby site at Giza, appears taller than his fatherâs, but this is an illuÂ¬sion; it is built on higher ground and was in fact, origiÂ¬nally at 447 .5 feet (136.4 m), 33.5 feet (10.2 m) shorter than the Great Pyramid.hufu â 2575-2566 BC. The largest of the three pyramids at Giza, known as the Great Pyramid, is truly an astonishing work of engineering. It was built over a twenty year period.