Help with story please?

OK, so I am in the process of writing the outline for an eight book modern fantasy series. It's about a boy who lives in Seattle with his elderly foster mother and is one day attacked by a horrendous creature. Someone --who turns out to be his uncle-- saves him from the creature and brings him back to his house, unconscious and in shock. He explains to him that he belongs in another world, where his parents were from. His parents, who died after being wrongfully exiled by and evil man. This world is a world of magical creatures and powers, where things are powered off of magical energy rather than electricity.

My real question is, where should this world-- or at least the part of this world that is in the USA-- be?

A. The Olympic National Park on the Olympic Peninsula in Washington which is one large mountain surrounded by foothills and forest

B. All along the Washingtonian section of the Cascade Mountains that run through the middle of the state, north to south with many mountains and forests.



A's Pros and Cons...

Pros, it is more isolated as it makes up most of a peninsula, so really only one side of it would be even open to 'our world.' It is more of a square shape which would make travel and everything easier. It also has only one road running through it.



Cons, It's three times smaller than the Cascade range as its about 30 miles wide and 40 miles long



B's Pros and Cons...

Pros, It is alot bigger, almost 200 miles long and has lots of mountains rather than one



Cons, It is only between 8- 30 miles wide and has 'our world' on two sides. It also has alot of highways and roads through it.Help with story please?
You could make up your own place for this world to be. Like another dimension or something like that. maybe one of those two places could contain the secret entry to this other world? You might not like that, maybe you want it to be a real place. But thats my idea anyway :)Help with story please?
I say that the peninsula would be best. It's more secluded and would be easiest to hide away from the mortal world, you know?



PS: I never did get that e-mail lol



But you know, no matter how much you spin this story, it'll still remind me of Percy Jackson somewhat.