Ever wonder what’s the difference between a national park, monument and forest? All this week, we’re breaking down the different types of America’s public lands and why they’re all so special. First up: National monuments – they protect a specific natural, cultural or historic feature. For example, the Sonoran Desert National Monument in Arizona is the most biologically diverse of the North American deserts, and its namesake monument protects an extensive saguaro cactus forest that visitors can hike through to see classic desert vistas. Photo of the Milky Way shining above saguaro cacti by Bob Wick, @mypubliclands