Ah, no, not like that. People have built a lot, that's all, there's more city than forest left, or coast, it's not strange for the city to only stop right when the sand of the beach starts. Mountains have been leveled down or pierced through to create tunnels so people reach places faster and even where there isn't city the forest has been altered to place roads for people to travel. Rivers are altered as well, their course is changed together with the rest of the land.

[It's supposed to be advancement but... No wonder she thought he meant it was destroyed, it sounds bad indeed.]

... Well, in a certain way it was destroyed but no one did it with that goal in mind or anything.