The second Brit - Parashat Ki Tavo - three set of stones? (Rashi)

Question

I am little confused trying to understand a Rashi. To Devarim 27:2, Rashi explains that there are three "memorial stones" of this ratification of the Brit between Israel and G-d. I don't see how he comes to three. I only see 2 sets of stones: Immediately after they crossed the Jordan and another set on mount Eibal. Why does he mentioned a third one?

This is the Rashi to Devarim 27:2: והקמת לך. בַּיַּרְדֵּן, וְאַחֲ"כָּ תּוֹצִיא מִשָּׁם אֲחֵרוֹת וְתִבְנֶה מֵהֶן מִזְבֵּחַ בְּהַר עֵיבָל; נִמְצֵאת אַתָּה אוֹמֵר שְׁלוֹשָׁה מִינֵי אֲבָנִים הָיוּ — שְׁתֵּים עֶשְׂרֵה בַּיַּרְדֵּן וּכְנֶגְדָן בַּגִּלְגָּל וּכְנֶגְדָּן בְּהַר עֵיבָל

Shkojach!

Answer 1

The gemarah sotah 35b lists the three stones.

One is a set that Moses erected in the land of Moav (Deuteronomy 1:5)... And there is one set that Joshua erected in the Jordan (Joshua 4:9). And there is one set that Joshua erected in Gilgal (Joshua 4:20).