At Zion National Park, the last half-mile to Angels Landing runs along a knife-edge ridge. Drops of about 1,000 feet fall away on both sides. A single metal chain, bolted into the rock for about a century, is the only handhold. So many hikers wanted to try it that Zion had to ration it. Since 2022, a daily lottery decides who gets a permit for that stretch. Winners still grip the same chain to reach the summit.