In Mass Effect 3 Dekuuna, the Elcor home world, is located in the Silean Nebula of the Milky Way in the Phontes System. The Elcor live in the grasslands near the equator. There are many natural resources on the planet including forests and precious metals, but they are protected by law.
The 2 capitals of Dekuuna are Sereuun and Malvuon. They alternate between the two during the wet season to the dry season.