Europe's most active volcano is sliding into the sea - 1

Half Dome, here in 1931, has long been an iconic feature of Yosemite, which was established as a national park in 1890 thanks largely to efforts by explorer and naturalist John Muir. "No temple made with human hands can compare with Yosemite," wrote Muir.

Giant chunks of rock have been falling from Half Dome. Here, in 1919, a group stands on a rocky outcropping off of the feature.

Half Dome as seen from the Glacier Point Hotel in 1933. The hotel, finished in 1917, stood 1,000 metres (3000 feet) above Yosemite Valley. After closing because of snow damage in the winter of 1968, the hotel burned down in an electrical fire in July, 1969.

Snow envelops Half Dome in this 1922 photo. It was declared “perfectly inaccessible” in an 1865 report, but 10 years later, hiker George Anderson reached the summit.

The nearly 750 thousand acre Yosemite National Park drew over 4 million visitors in 2014. Here, in a 1965 photo, tourists snap pictures of the stunning granite peaks.

Rockfalls have changed the face of Half Dome, and climbers are adjusting to altered routes. This photo shows an ascent in 1974.

This 2010 photo shows Half Dome poking through the clouds. Hikers should not to attempt the climb if storm clouds are in the area. In 1985, lightning struck the peak, killing two hikers and injuring two more.

Half Dome juts over 1,650 metres (5,000 feet) above ground, almost 3,000 metres (9,000 feet) above sea level, attracting climbers who BASE jump from Half Dome.

Dean Potter, who died in a wingsuit accident in 2015, climbs Half Dome in 2012. After the 2015 rockfalls, a climber said it felt like Half Dome was mourning Potter.

Tourists sometimes wear gloves to clutch at the cables as they climb Half Dome’s final ascent, ditching them on the way back down. When hikers don’t pack out their gloves, "hundreds of pounds of rotting gloves...accumulate."

Rock climber, Alex Honnold, famous for his climbs without ropes or harnesses, walks a 13-metre (40-foot)-long sliver of granite on Half Dome named the Thank God Ledge.

The climber first to climb Half Dome without a rope is taking the rockfalls in stride. “It’s always a little sad to see a classic route change, [but] it’s kind of the nature of rock to change over time,” Alex Honnald says.