Idfu (ĭdˈfō) [key] or Edfu ĕdˈ–, town (1986 pop. 45,737), S central Egypt, on the Nile River. It is an agricultural trade center and has paper mills and a sugar refinery. Idfu was the capital of a predynastic upper Egyptian kingdom that flourished c.3400 B.C. and worshiped Horus. Later, a large sandstone temple of Horus was built there by Ptolemy III and Ptolemy IV. It is one of the finest extant examples of Egyptian temple architecture. Excavations have yielded a field of mastabas dating from the Old Kingdom, a Roman necropolis, and Coptic and Byzantine remains. The town was known to the Greeks, who identified Horus with Apollo, as Apollinopolis Magna.