Great Pyramid of Giza

Tomb of the pharaoh Khufu, built around 2570 BC, the only survivor of the seven wonders of the ancient world. It stood 147 metres tall originally (138 today, with the tip gone) and is made of some 2.3 million limestone blocks averaging 2.5 tonnes each. It was the tallest building in the world for almost 3,800 years, until Lincoln Cathedral overtook it in 1311.