It is thought that, at construction, the Great Pyramid was originally 280 Egyptian cubits tall (146.5 metres (480.6 ft)), but with erosion and absence of its pyramidion, its present height is 138.8 metres (455.4 ft).
Each base side was 440 cubits, 230.4 metres (755.9 ft) long.
There are three known chambers inside the Great Pyramid.
The lowest chamber is cut into the bedrock upon which the pyramid was built and was unfinished.
Based on a mark in an interior chamber naming the work gang and a reference to fourth dynasty Egyptian Pharaoh Khufu, Egyptologists believe that the pyramid was built as a tomb over a 10 to 20-year period concluding around 2560 BC.