Route 1

This is the first route you will face on your journey towards becoming a pokemon master! Or maybe it's a journey towards collecting only the cutest pokemon? Whatever floats your boat. ¯\_(ツ)_/¯

Pokemon
The pokemon in the mainland of Route 1 and the cave are the same.

Event
Route 1 is also where the Primal Groudon Event takes place! If you talk to the green-shirted dude standing in front of the red lava, he will tell you how many more seconds there are until the event starts. When is does start, the red lava will open up, and beneath it will be a cave.