The Holy Tree is the symbol of the Elf Race, the symbol of the Elf Royal Court, and most of the elves living inside are from the Elf Royal Family.
In other words, this is the most prestigious place of the entire Elf Race.
No matter how poor and destitute the Elf Race might become, they would never open its interior to outsiders.
After all, the Holy Tree is also equivalent to the political center of the entire Elf Race as a whole; generally, such a place is impossible to open to the outside, unless the Elf Race has already declined to the level of a tiny duchy.
Obviously, things haven't reached that point yet.
So the surroundings of the Holy Tree are heavily guarded.
Just like the palace of the Ista Empire, patrols led by Tier Four Mages can be seen everywhere, and from time to time one can even see what appears to be Tier Five Mages moving about inside.
It's quite possible that there are even Tier Six Mages inside guarding the Holy Tree.
