The doors to the world have been flung wide open, and the view that’s available is staggering.
Upon checking flung - throw, cast or move quickly does not fit with this sentence. staggering deeply shocking! it is from the book “the one thing”
To fling or throw something open is to open it suddenly and completely.
The important point is that it is referring to the doors when it says flung wide open.
This is metaphorical. They are using "doors to the world" as a metaphor (and what for I couldn't tell you without more context - there's a few possibilities), and saying they have been opened suddenly and completely, possibly forcefully. Now they're open, it say, the view through them is staggering - and that's still metaphor.