To fully enjoy the Simien Mountains, I did a day trek here. From the town of Debark, they bring you deep inside the park, and in the company of a guide and a scout (with a gun), you can go hiking. The narrow paths circle around the mountain ridges, through grasslands.
In the park, several species of wild animals can be found. Most appealing are the baboons. They can be seen in groups, on cliffs and ridges. It took me almost the whole day to see some of them close up, but on my way back (around 6 pm) groups finally became active and in full view.
The best parts of the Simien mountains to me were the views and the canyons. And also its quietness: it is unusual for Ethiopia, not many people live here.