13 During the 12th century, Kurdish ruler Al-Aziz attempted to destroy the pyramids, and he actually succeeded in damaging them.

Near the end of the 12th century, Al-Aziz attempted to destroy the Great Pyramids. His workers, who were unable to remove more than 2 stones a day found the process to be more of a liability than to build the actual pyramids themselves. (1,2)

14 Regardless of the heat around it, the temperature inside the Great Pyramids stays relatively the same.

The air shafts built into the pyramids allow the pyramids interior temperature to remain at a constant 68 degrees Fahrenheit (20 degrees Celsius). (source)

15 Since 1983, it has been widely debated on whether or not the Great Pyramids align with Orion’s Belt. 

This idea was brought forward by Robert Bauval and it has been challenged by Bauval’s critics. Ed Krupp of the Griffith Observatory believes that certain irregularities between the stars and the pyramids make the idea invalid. (source)

16 The pyramid of Giza actually has 8 sides, but the this can only be seen from the sky.

The center of each main side is indented, thus making the pyramid have 8 sides. It’s not visible to the naked eye and is best seen from above when the sun draws shadow on it. (source)

17 Scientists and historians have been able to figure out what the Great Pyramids may have looked like years ago.

Being made from polished limestone, the pyramids would reflect the sun, thus emanating a beacon of light that could be seen from miles away. (source) 

18 Most Aztec pyramids are open to the public for exploration.

Five archaeological parks are open to the public. Out of the five, Teotihuacan is the most prominent giving that it contains the Pyramid of the Sun and the Pyramid of the Moon which are two of the worlds largest pyramids. (source)