Stone monument in the shape of a needle, with the top in the form of a pyramidion. Obelisks were solar symbols, and have been interpreted by some scholars as the representation of a sunbeam. The top was usually gilded and reflected the light of the sun. Solar apes were often depicted on the base, baboons worshipping the rising sun. These animals were known to greet the sun each morning with loud cries. The obelisk originated in Heliopolis, the centre of the solar cult, and later became a regular feature of temples throughout Egypt. The most famous are those erected in pairs in front of the pylons of temples from the New Kingdom and later. Obelisks were also erected in the Old Kingdom, but had, much smaller in size, among other places in front of private tombs. One of the largest obelisk-shaped constructions was in the sun temple of Nyuserre at Abu Gurab, although this was rather stocky in shape. The manufacture, transport and erection of an obelisk was an immense task. The huge monoliths, weighing hundreds of thousands of kilos, were often more than 30 metres tall. The largest obelisk ever begun, which was abandoned when the stone cracked (the well-known 'unfinished obelisk' in the quarries at Aswan) is almost 42 metres long. Many obelisks have been moved, not only within Egypt itself but also to other countries. The Assyrian king Assurbanipal already transported two obelisks back to his own country. The obelisks that now stand in New York and London both came from the Caesareum of Cleopatra VII and Augustus in Alexandria, where they had previously been transported from the temple of Thutmosis III for Re-Atum in Heliopolis.