“Seeing the return of natural landscapes is a very inspiring thing,” said Christine Lehnertz, president and CEO of the Golden Gate National Parks Conservancy, which has worked to bring these and other projects in the Presidio to pass. “One piece at a time adds up to so much more.”

The Rock's is full of unexpected finds, among them is a rare and tenacious rose. And this rose has a remarkable story.

"There's less people around, so you can kind of enjoy San Francisco almost like a local," said Santos, standing in line for the Alcatraz ferry on her third visit to the city. "It's a little bit refreshing, actually."

Here’s how a desolate rock in the middle of San Francisco Bay became a tourist hotspot—and horticultural haven.

The move comes after the National Park Service, which owns Alcatraz, has been steadily reopening other national parks, including Yosemite, Muir Woods, Sequoia-Kings Canyon, Pinnacles and others, often with reduced visitation and closed visitor centers.