Addis Ababa is Ethiopia's high-altitude capital (2,355 m above sea level) and Africa's diplomatic hub — home to the African Union headquarters, the National Museum of Ethiopia (housing Lucy, the 3.2-million-year-old Australopithecus afarensis fossil discovered in 1974), Merkato (Africa's largest open-air market), and the ceremonial birthplace of the world's coffee tradition.
Don't expect a typical African capital. Addis is cool, hilly, Orthodox-Christian, coffee-obsessed and deeply Ethiopian — a country that was never colonised, that runs on its own 13-month calendar and its own 6-hour-offset clock, and that eats injera and tibs like the rest of the world eats pasta. Come for a weekend of coffee ceremonies, museum visits and Ethiopian jazz; stay for a springboard to Lalibela, the Simien Mountains and the Omo Valley.
Most travellers give Addis Ababa 2–4 days on the way to the historic north or as a stopover on the Ethiopian Airlines hub route. That's enough to eat properly, see Lucy, drink your body weight in Yirgacheffe and understand what makes Ethiopian culture unique before flying on.