[[File:Knatchbull M (capt the Hon) Collection Q44314.jpg|thumb|300px400px|View of Achi Baba from the front line trench. Gallipoli, 29 April 1915.]]
'''Achi Baba''' (''Turkish'' '''Alçi Tepe''') is a height dominating the [[{{gw|Gallipoli]]}} Peninsula in [[Turkey]]. It was the main defensive position of the Ottoman Turkish defences during the First World War Gallipoli campaign of 1915.