The Great Sphinx at Giza, one of the many monuments that we have come to consider an icon of the Ancient Egyptian civilisation, lies northwest of the Valley Temple of the Pyramid Complex of Khefren.

Right in front of the Sphinx, and directly north of the Valley Temple, an open structure was erected. As this structure appears to be very closely related to the Sphinx, archaeologists consider it to be the Sphinx Temple, but the precise function of this unique structure remains unclear to this date.

Map of the Pyramid Complex of Khefre, showing the location of the Sphinx and its temple.
Source: Lehner, Complete Pyramids, p. 124.

Clickable map of the Sphinx and the Sphinx Temple.
Source: Lehner, Complete Pyramids, p. 129.
 

A close geological study of the sphinx and the nearby temples has revealed that the large blocks which were used to build the Valley Temple of Khefren's complex were most likely quarried from the layers that run through the upper part of the Sphinx's body.

The core blocks that were used to build the Sphinx Temple temple, on the other hand, came from just below the chest height of the Sphinx's body.

This means that the Sphinx was sculpted at almost the same time as when the Valley Temple and temple in front of the Sphinx were built. As the Valley Temple was built as part of Khefren's Pyramid Complex, it thus stands that the Sphinx was sculpted out of the rock during Khefren's reign as well.

The Great Sphinx, with the pyramid of Khefren behind him.