Aenon in the New Testament
Aenon was the place where John the Baptist was baptizing "because there was much water there" (Jn 3:23). It was on the west side of the Jordan, the place where John baptized at the first being on the east (Jn 1:28; 3:26; 10:40).
We may be sure it was not in Samaritan territory. Eusebius, Onomasticon locates it 8 Roman miles South of Scythopolis (Beisan), this stretch of land on the west of the Jordan being then, not under Samaria, but under Scythopolis. Its position is defined by nearness to Salim.
Various identifications have been suggested, the most probable being the springs near Umm el-`Amdan, which exactly suit the position indicated by Eusebius, Onomasticon.
International Standard Bible Encyclopedia, which is in the public domain (with minor edits).