Shades of Sitchin, the Bosnian Pyramid of the Sun, discovered in 2005, is 722 feet taller than the Great Pyramid of Giza. Radio carbon dating shows the pyramid to be at least 24,800 years old.
Professor Joseph Davidovits, mentioned several times on this thread, is involved in studying the pyramid.
Material Analysis shows that the structure is composed at least partially of man-made concrete.