How do you get to the cave with Mewtwo in Y?

Question

I went to Pokemon Village in Y and saw the cave opening in the top left corner but there was a ledge in front of it. I really want Mewtwo. (I gave up on getting Zapdos because it kept moving to the complete other side of the map ) How do I get there? EDIT: I did beat the E4 and the Champion

Answer 1

This video from IGN should help you with finding that Mewtwo.

Tl; dw In short, just Surf up the river, and land to the right, just before the Waterfall.