Awash National Park is Ethiopia's classic Rift Valley park: acacia scrub, dry savanna, volcanic rock, hot springs, and the Awash River dropping into a gorge before pushing east toward the Afar lowlands. It is much easier to reach than the country's remote parks, sitting on the Addis Ababa-Dire Dawa road, but it still feels properly wild once you leave the highway behind.
The park is not a Serengeti-style wildlife spectacle. You come for the whole mix: beisa oryx and Soemmerring's gazelle on open plains, birdlife along the river, Awash Falls, the volcanic bulk of Mount Fentale, and palm-shaded Filwoha Hot Springs. It is a good first Ethiopian safari precisely because the distances are manageable and the landscapes change quickly.
Awash is best done with a vehicle, a driver, and a local guide who knows the park roads. Heat is a serious factor, especially in the dry season, and the highway/railway corridor cuts through the protected area, so do not expect untouched wilderness everywhere. Come with realistic expectations and it is one of the easiest ways to see Ethiopia's Rift Valley ecology up close.