The Bolivian Gate of the Sun sits amidst the ruins of the ancient town of Tiahuanaco, also known as Tiwanaku. Not much is known about the people who lived there, other than the fact that they had a distinct culture and built their civilization near Lake Titicaca. The area flourished between 14,000 B.C. and 900 A.D., although archeologists are uncertain of its exact age and size.
The Tiwanaku calendar, which some archeologists speculate is on the gate itself, apparently featured a shortened year of 290 days. Contrary to other attempts at reconstructing a new fixed calender, the sun gate calendar consists of 12 periods or months, each of which has been broken down into 24 days. The Gate of the Sun is a large stone block with carved details. It measures 13 feet by 9.8 feet, and weighs an estimated 10 tons.
According to some ancient astronaut theorists, the gate of the sun conspiracy stems from the belief that aliens from another planet visited Earth at various points in time. They might have visited Tiahuanaco, and played a part in the creation of Gate of the Sun monument.
Archaeologists are able to determine where water levels were in the past by studying the striations and other markings in the soil and rocks. They used these methods when determining that Tiahuanaco, which now sits around 800 feet above sea level, was once a port city surrounded by Lake Titicaca. The lake is now a whopping 12 miles away from the site but in the past it was much larger. The Gate of the Sun is a part of this ancient port city, although no one has discovered its true purpose.
At the top of the gate there is a square-shaped face carved into the stone. Below the face is a stout body with arms. The figure's hands are holding two perpendicular pieces of wood, stone, or even bones. Archaeologists aren't quite sure who this is supposed to be. It could possibly be the face of Viracocha, an Incan god. According to the stories, Viracocha was the highest of the Incan gods, as he created all of the others that they worshipped. The figure might also be a sun god of some sort, based on the striations carved into the rock around his face. They believe these might be the rays of the sun. Of course, the ancient astronaut theorists think that instead of the sun's rays, this actually a depiction of the god going through some sort of inter-dimensional gateway to another planet. The figure is also called the "Weeping God" because of the marks on his face that resemble tears.
The remarkable thing about the Gate of the Sun is that is made from one single stone block. Archaeologists were unable to find any seams that would indicate it's made of multiple pieces put together. It does have a crack in it, though, most likely from age.
Unlike other ancient works, such as the Pyramids in Egypt, which are made from many different stone blocks that have been pieced together, the Gate of the Sun is a single entity. Archaeologists discovered that the stone, which weighs 20,000 pounds, is made of andesite. This type of stone is volcanic and found in the Andes Mountains, hence its name.
One of the puzzling things about the Gate of the Sun is the fact that it is very precisely carved, even though the people who made it only had hand tools. This led some ancient astronaut theorists, who believe that advanced cultures from other worlds visited the planet regularly during prior time periods, to suggest that these advanced aliens played a part in creating the gate.