Pallet town Question

[Hyatt]

I've been wondering this for a while. And now that I have pictures, I tried once again attempting this
Where is Professor Oak's lab in relation to Ash's house? I know to the left of Ash's house is an intersection and usually you see people going on the road in the opposite direction of Ash's house
Here's a pic of what I'm talking about
However when we see Prof Oak's lab, we just see the front entrance, the two paths that run around the perimeter of his property and that bridge.
So basically I'd like to know, what road leads to Prof Oak's lab and what one leads to Viridian?
I'm not sure if there is an answer to this, I just kinda want to make sure. I was thinking of making a sprite map of Pallet town in it's anime form.

 

[Dan2]

I think the mountains in the distance might be a clue.

 

[AkivaraII]

In the "world of Pokemon" intro thingy that replaced the Pikachu shorts for the dub starting with 4ever, it's got a shot showing Ash's house and Professor Oak's lab. It's the top fork.