Since ancient times, the use of river energy has been an important factor determining the development of civilization. In this long way of the development, the water engine, from the simplest water wheels used in the ancient world to supply water for irrigation, and water mills, transformed into modern hydraulic units for hydropower plants.
Since ancient times, the pyramids of Egypt excite the minds of people with their mystery, form and magical effect on people and objects. It is still unknown who built them. The principle of operation and the purpose of the pyramids is a mystery as well.