858 El Djezaïr

858 El Djezaïr is a stony asteroid from the asteroid belt, about 24 kilometers in diameter. It was discovered on May 26, 1916, by French astronomer Frédéric Sy at the Algiers Observatory in Algeria, North Africa, and given the provisional designation 1916 a.

The asteroid orbits the Sun at a distance of 2.5–3.1 AU once every 4.71 years (1,722 days). The bright S-type asteroid has a very high geometric albedo of 0.32. Its rotation period has been measured to take 22 hours and 20 minutes. Along with the asteroids 68 Leto and 236 Honoria, it is a member of the Leto family, a small, well-defined group of asteroids, all with a semi-major axis of close to 2.8 AU.

El Djezaïr is the French spelling of the Arabic name for Algiers, the capital of Algeria. It means "the islands". The asteroid was the first minor planet to receive a name that consists of more than one word. Its designation, 1916 a, is a superseded version of the modern two-letter code system of provisional designation, implemented just a few years later in 1925.