The Jordan Valley
In the Madaba Map the mountains Ebal and Garizim are shown twice, once near Galgala, in the Jericho region, and once near Nablus. The mosaicist was well aware of the existence of two traditions: the Samaritan and the Jewish one (followed also by the Christians) and, apparently, choose not to choose between them. See no. 42.
13. Ebal - (Mount Ebal)
The reference to Gilgal in Deut 11:30 remains enigmatic. The preceding verse gives the distinct impression that reference is being made to a location somewhere in the vicinity of Mount Ebal and Mount Gerazim, that is, near ancient Shechem. This is further strengthened by the reference to the Oak of Moreh, which Gen 12:6 clearly locates at Shechem. Thus, it seems that an as yet unidentified location somewhere in the vicinity of Shechem also bore the name Gilgal. Perhaps this is the same Gilgal as that known to Elijah and Elisha. However, many scholars feel that the overall context of this verse, referring as it does to entrance into the promised land, requires that Gilgal near Jericho be the point of reference. One provocative idea relates these verses in Deuteronomy to a rabbinic tradition suggesting that the Israelites utilized artificial heaps of stone as replicas of Ebal and Gerazim as part of a cultic celebration at the more famous Gilgal (Brownlee ISBE 2: 471).
Wade R. Kotter, The Anchor Bible Dictionary, ad v. "Gilgal (Biblical Place)" (extract)
Herbert Donner (The Mosaic Map of Madaba, Kampen 1992, 24.48)
The mountains Gerizim and Ebal are represented twice on the Madaba Map: near Jericho and near Neapolis. What has happened here? The problem can be solved on the basis of Eus. On. 64:9-14 where, strangely enough, both mountains are indeed located near Jericho. Eusebius, however, does not fail to add: "The Samaritans show other ones near Neapolis, but they are wrong, for the mountains shown by them are too far from each other, so that it is impossible to hear one´s voice when calling to each other."
Although this seems to be entirely intelligible and is confirmed by Deut. 27, the Samaritans were by no means wrong. Eusebius was wrong, and everybody knew it, perhaps he himself included. The Samaritans laid claim to the mountains, considering them to be their own holy mountains. Hostility to the Samaritans forced the orthodox Jews in Jerusalem to locate both mountains at another spot, for the Samaritans were not allowed to be right. Eusebius followed the orthodox Jewish tradition. The mosaicist, however, being well informed, preferred a Solomonic solution: he listed the mountains twice, indicating by larger letters that he regarded the location near Nablus as being correct.
Map Section 2 Place Sources