Ethiopia’s premier trekking and walking destination, the 412 km2 Simien Mountains National Park was inscribed as the only Natural World Heritage in Ethiopia in 1979, whereupon UNESCO lauded it as “one of the world’s most spectacular landscapes, with jagged mountain peaks deep valleys and sharp precipices dropping some 1,500m”. In addition to the splendid scenery and hiking opportunities, the Afromontane meadows and moorlands of the upper Simiens also form one of Ethiopia's most important biodiversity hotspots, populated by an alluring wealth of endemic plants and animals including Walia ibex, gelada baboon and Ethiopian wolf. The dramatic landscapes of the Simen Mountains (i.e. the extreme escarpments and their thousands of meters of sheer cliffs) are the result of massive seismic activity in the area about 40 million years ago (Miocene and Oligocene, geological period). Ever since, this massive complex (a 3000m-thick molten lava outpour) has been going through tectonic activities (faulting, folding ... during tertiary period), glaciations/ice cover and uplifting. Subsequently, erosion over the millennia has resulted in the rugged landscapes of the Semien Mountains (Hurni H., Ethiopia 1986). Climate The mean annual rainfall is 1,550mm falling in two wet seasons, from February to March, and July to September which is said to have become much lower since the 1960s (Margin, 2001). Temperatures range from a minimum of -2.5‹C to 4‹C to a maximum of 11‹C to 18‹C. There are often drying winds during the day; frosts may occur at night, and snow sometimes settles on the summit of Ras Dashen. Flora Due to variation in altitude and topographical features, the vegetation in Semen Mountain is characterized by four different altitudinal belts; namely: Afro alpine moorland (3700-4400 MASL), Ericaceous moorland/sub alpine highland (2900- 3700 MASL), mountain forest belts (2000-3000 MASL), and savanna belt (below 2000mast).

The endemic giant lobelia rhynchopetalum and festuca gilbertiana, Giant heather, erica arbora, hypericum revolutum , hypericum quartinianum, Juniperus procera, Hygenia abyssinica, Olea chrysophylla, and Papanea simensis are dominant species, to name a few. Species which are traditionally recognized as having 'medicinal' value include: Hygenia abyssinica, giant lobelia, Synoglossumlanceolatum, or Giometricum, phytolaca Dodicandra, Thymus serrulatus, Myrsine Africana, Achyranthus aspera, Kalanchoe deficiens, Zehnaria scabro, Conium maculatum, Fauna Though the park is home for 32 mammals and 182 bird species, Semen is known more by the richness (high rate) of endemic than species diversity, as there are 11 endemic mammals and 6 endemic bird species, each accounting for 32.2% and 37.5% of the country's endemic mammals and bird species, respectively.

Simen is one of the parks that make the country 'center of endemic' in East Africa, next to Madagascar. The 4 endemic large mammals of the park, which account for 57% of the country's endemic large mammals, are: Wallia Ibex capra ibex Wallia with a population of 623 as of 2005 (endemic to Semen only), Ethiopian wolf canis simensis with a population of 78 as of 2005 , Gelada Baboon more than 4000, Minilik Bush buck - still questionable. Besides, the park is also home for other large mammal species, such as: Klipspringer, Leopard, and common jackal. In addition to large and small mammals there are also 6 endemic bird species in the SMNP, namely; Spot breasted plover, Abyssinian long claw, Abyssinian cat bird, Black headed siskin, Abyssinian woodpecker and Ankober Serine.

 The best way to explore the Simien Mountains is on foot or mule back several overnight options are available. The 3-day trail connecting Sankaber, Gich, Imet Gogo and Ayna Meda is recommended to those whose main interest is endemic wildlife. For peak-baggers, the ascent to the summit of Ras Dejen could be undertaken as a 3-day hike from Chennek. For those with limited time, it is possible to drive east from Debark to Chennek along an all-weather road, and to exit the car for short walks.