We’ve explored Yosemite Valley a lot — for good reason. It’s an outdoor wonderland where people raft, hike and climb cliffs. In this episode, Ezra tours Yosemite Valley on a "green dragon" — an open-air tour bus — and also learns about rock falls and why historic places in the park have been renamed. He also visits what people call Yosemite Valley’s "twin sister." It’s a place that John Muir fought to preserve — but he lost that battle.