Despite being one of the most famous and most-visited attractions in the United States, Grand Canyon National Park still holds some surprises. Here are a few facts about the Grand Canyon you probably don’t know.

4. There are no dinosaur bones in the Grand Canyon

The Grand Canyon might look like the perfect place to go looking for dinosaur bones, but none have ever been found there, and for good reason. The rock that makes up the canyon walls is vastly more ancient than the dinosaurs – about a billion years more ancient, in some cases – but the canyon itself probably didn’t form until after the dinosaurs were long gone.

The Grand Canyon
The Grand Canyon