Isna (ĭsˈnə) [key] or Esna ĕsˈ–, town (1986 pop. 43,055), central Egypt, on the Nile River. It is the center for an agricultural area that is irrigated by the Nile. Isna's manufactures include cotton fabrics and ceramics. The Ptolemaic temple (with Roman additions) to the ram-headed deity Khnum is the town's outstanding monument. Nearby is a Coptic Christian monastery, said to have been founded in the 4th cent. to commemorate those martyred by Diocletian, but now believed to date from the 10th or 11th cent.