The Atlanta Zero Mile Post is a stone marker which marked the terminus of the Western and Atlantic Railroad in Atlanta. It is approximately 1 foot wide on each side and 42 inches tall. It is inscribed on one side with the text "W & A RR 138" and on another side, "W & A RR OO". It is located in the basement of a disused building in Downtown Atlanta, within the Underground Atlanta Historic District, under the Central Ave. viaduct, between Alabama and Wall streets.