The Stele provides an additional 2 Faith production, giving a big boost in the early game toward religion. Also, it is available right from the start of the game, allowing the Ethiopian player to start producing Faith earlier than anyone else (except the Celts, of course). It is advisable to build it first thing in each new Ethiopian city.
A Stele is a large, upright slab of stone or wood used as a monument to commemorate great leaders, victories in battle, or occasionally to mark territorial boundaries. Found throughout Ethiopia and the surrounding regions, the stelae were often intricately inscribed with the details of the person or event being memorialized. The Obelisk of Axum, one such stele, was constructed in the mid-4th century AD in the Ethiopian city of Axum, but was later broken down and shipped to Italy during the occupation of Ethiopia by Mussolini's forces. Standing over 23 meters (75 feet) tall and weighing 150 tons, the great stele was returned to Ethiopia and reassembled in 2008 as part of an effort by the United Nations Educational, Scientific, and Cultural Organization.