Small, random questions about RotE that still bother you (spoilers all RotE books)

[Valarya]

What do you think of this theory?

I like it, but it seems like every single person in the books, thus far, has commented consistently on the memory stone as building-material as such:

"how did they shape it so big and how on earth did they move it/set it in to place!?"

One theory I've always had was the massive trees in the Rain Wilds themselves. We know that the murky ground of the forest next to the river is also mucked up with acidic River Water in that it eats at people's shoes in the short-story of the Rain Wild settlement. If the acidic water has been in and around the roots of those trees for hundreds of years... are not they impervious?

One comment is made that the Khuprus family chose their tree when they first came to the Rain Wilds and their homes are still build on and around that tree... it must have been standing for a LONG time in all that acid water....