Ethiopia is a fascinating county both geographically and culturally, it is also relatively easy and economical to trek in the country especially when compared to its neighbors Kenya and Tanzania to the south. The two most well known trekking destinations in Ethiopia are the Simien mountains in the north and the Bale mountains in the south. The Simien mountains are generally drier and have a spectacular eroded shear face towards the Eritrean plains. Scenically I'd give the edge to the Simien mountains, but wildlife wise the Bale Mountains may be a slightly more attractive and if you want to see the endangered rare Ethiopian Wolf, Bale is the place to go.