Workers removed graffiti inside the pyramid, repaired cracks and cleaned the walls of salt residue, the Supreme Council of Antiquities said on Thursday.
The council said visitors increase humidity inside the pyramids through breathing and perspiration, which deposits salts on the plaster and ruins the walls.
The giant stone structure was built for the 4th Dynasty King Khafre (2575-2551 BCE), known as Chephren by the Greeks. It measures nearly 216m on each side and was originally 143m high.
Since 1995, the council has closed one pyramid at a time for
The statement said the third and smallest pyramid, Menkaure
(Mykerinus), will now be closed for a year.
The oldest pyramid of the group was built for Khufu (Cheops),
the second king of the 4th Dynasty. Called the Great Pyramid, it is the largest, with the length of each side measuring 230m and its original height 147m.