Hokage Rock

The is a mountain overlooking Konohagakure that has all the faces of the Hokage carved into the stone. It was envisioned by Hashirama Senju as a symbol that the Hokage would always watch over the village.

Adding a Hokage's face to the monument apparently takes time, as the Fifth Hokage's face is not added until some time during the timeskip (in the anime, it is added by episode 187 of the original anime). The anime suggests it doesn't actually take too long, as the Stone Carver adds first Danzō Shimura's face and then Kakashi Hatake's face to the monument prematurely, in turn forcing him to remove their faces once they are not officially given the position. Similarly, faces can be added to the monument before a Hokage officially takes office, as the Sixth Hokage's face is added to the Hokage Rock before he agrees to accept the responsibilities of the office.

Trivia

 * The monument is similar to Mount Rushmore, which features sculptures of the heads of four United States presidents.