Pyramid
A pyramid is a building where the outer surfaces are triangular and converge at a point. The base of a pyramid can be trilateral, quadrilateral, or any polygon shape, meaning that a pyramid has at least four faces (base plus at least three triangular faces). The five-face square pyramid is a common version.
A pyramid’s design, with the majority of the weight closer to the ground, means that less material higher up on the pyramid will be pushing down from above: this distribution of weight allowed early civilizations to create stable monumental structures.
For thousands of years, the largest structures on Earth were pyramids: first the Red Pyramid in the Dashur Necropolis and then the Great Pyramid of Khufu, the only one of the Seven Wonders of the Ancient World still remaining and still the tallest pyramid of all. The largest pyramid ever built, by volume, is the Great Pyramid of Cholula, in the Mexican state of Puebla. This pyramid is still being excavated. source : wikipedia
It is great building in the past, where there is no hi-tech technology to build a amazing building. What do you think about it? 
