Hamadryas Baboon (Papio hamadryas) is a baboon from the Old World monkey family. It is the northernmost of all the baboons; its range extends from the Red Sea in Egypt to Eritrea, Ethiopia and Somalia. It also lives on the Arabian peninsula (Saudi Arabia and Yemen). The Hamadryas Baboon was a sacred animal to the ancient Egyptians as the attendant of Thoth, and so, is also called the Sacred Baboon.
At Singapore Zoo, there's an exhibit called 'Hamadryas Baboons - The Great Rift Valley of Ethiopia' where you get to see these primates...