Built more than 4,500 years ago, the Pyramids at Giza are monumental tombs where ancient queens and pharaohs were buried.īut how, exactly, did the Egyptians build these things? The Great Pyramid is made of millions of precisely hewn stones weighing at least two tons each. Just outside Cairo, in Giza, the most famous of Egypt’s pyramids rise from the desert. And in addition to being visible from the air, the shapes can be seen from surrounding foothills. First studied in the early 1900s, the designs were initially suspected to be aligned with constellations or solstices, but more recent work suggests the Nasca lines point to ceremonial or ritual sites related to water and fertility. Called geoglyphs, these enigmatic designs are made by removing the top, rust-colored layer of rocks and exposing the brighter white sand underneath. Turns out, it’s rather easy to understand the how. Otherwise, how would an ancient culture have been able to make such huge designs in the desert without being able to fly? And why? Scientists suspect the Nasca drawings are as many as two millennia old, and because of their age, size, visibility from above, and mysterious nature, the lines are often cited as one of the best examples of alien handiwork on Earth. The biggest shapes stretch nearly 1,200 feet across and are best viewed from the air. The longest of the lines run straight as an arrow for miles. Joining them are 300 geometric shapes and 70 figures of animals, including a spider, monkey, and hummingbird. On a high and dry plateau some 200 miles southeast of Lima, more than 800 long, straight white lines are etched into the Peruvian desert, seemingly at random. More recently, archaeologists have uncovered traces of the rope-and-lever system the Inca used to transport stones from their quarries to their cities-a system that relied on strength and ingenuity, rather than alien architects. In fact, Sacsayhuamán isn’t the only example of this intricate masonry: Similar walls exist throughout the Inca Empire, including one in Cusco where a 12-angled stone has been carefully wedged into place. How an ancient culture accomplished such a feat of engineering is a fun little problem to solve turns out the Inca were as adept at building houses and fortified complexes as they were at watching the sky and keeping calendars. The 1,000-year-old interlocking fortress walls are made of rocks that weigh as much as 360 tons each, and which were carried more than 20 miles before being lifted and fit into place with laser-like precision. Built from enormous stones that have been chiseled and stacked together like a jigsaw puzzle, some say Sacsayhuamán could be the work of an ancient civilization that had a little help from interstellar friends. Outside the old Inca capital of Cusco, a fortress called Sacsayhuamán rests in the Peruvian Andes.

Ancient space travel