What other sacred/legendary places exist that are like Mount Myoboku, Ryuuchi Cave, and Shikkotsu Forest?
We know that there are other types of creatures, Gai summoned a turtle, Temrai summoned a weasel, and I'm not even beginning to talk about Pain's Chikshodo.

However, as for the "homes" of said summoned creatures, only 3 have been confirmed. The 3 you listed.


Mount Myoboku
Ryūchi Cave
Shikkotsu Forest