Herodotus on Moiris (Amenemhat III)

Herodotus records that Moiris constructed a gateway to the temple of Hephaistos (Ptah) and dug a large lake. In the lake he built more than one pyramid. Diodorus Siculus mentions a king named Moeris who dug out a lake "of remarkable usefulness" to provide a reservoir of water and guard against a poor inundation. He confirms that the place was named lake Moeris (in the Faiyum) after its creator. He is generally considered to have been Amenemhat III, who built a series of great water wheels in the Faiyum diverting the Nile into lake Moeris, and established a pyramid at Hawara (nearby).

Herodotus: Pharaohs