What other sacred/legendary places exist that are like Mount Myoboku, Ryuuchi Cave, and Shikkotsu Forest? The locations that have been mentioned where one can learn sage mode are:


Mount Myoboku
Ryuuchi Cave
Shikkotsu Forest


I am interested to know if any other places exist that are on-par with these places, such as a place where a legendary event has occurred. (Example: A place of hawk, summoned by Sasuke while fighting against Danzo).
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