Home town has a lake in it, but little do we know that you can use Dive in it
(Bring back Dive as a HM!!!)
Then the pathways, only one gym is accessible, where as the 2nd one (a forest) needs cut. The town in the last one has a river across it, but the bridge recently broke down when a tree fell on it...
hows that to start? Then you can continue going around to the 2nd town, curling around 'til you get dive... Then you arrive home, use Surf to get to that town, then Waterfall to reach the e4