Ok then, how do you explain the land formation in Past Bichon?
In past Bichon there are no forests, there are huge rock formations and the river does not run through the middle like it does in Present Bichon.
It takes 100s of years for forests and rivers to change the land and even longer for rock formations to change.
*Copyright to Rocky the *****
The only tree I could argue which would've taken years to grow is Ginko Tree, all other trees within Bichon could at most be 100 years old. But heck.. we have ****ing wizards who can make walls of fire bro, anything is possible.
As for the river, its obvious that this was man made to allow for an extra line of defence around Bichon Wall, and the excess soil was used to alter the coastline of the current & new bichon.
The missing rock piles would've been mined and used to build what is Bichon Wall & Castle.
The existing PB canyon network later became Serpent valley and allowed connections to Mongchon.
East Gorge was closed off and lost, but lower parts form Hell Province.
Mic Dropped.