Surprisingly, despite modern technologies and the development of science in the world today, there are many unidentified secrets associated with ancient civilizations. Many scientists believe that we are unlikely to solve them, writes travel.tochka.net.
Newgrange, Ireland. The monument was found by road builders in the 17th century, however, its study began only three centuries later. As a result of the excavation, a mound was discovered: it is perfectly round, with an impressive diameter, experts say that it is older than the Egyptian pyramids.