The Hebrus Valles are an ancient system of troughs and valleys in the Amenthes quadrangle of Mars, located at 20.2° north latitude and 233.4° west longitude. They are 317 km long and were named after a river in the Balkans which runs through present day Bulgaria, Greece and Turkey. Some authors have identified the troughs and valleys of Hebrus Valles as outflow channels, but their origin and history remain ambiguous.Carr, M.H. (2006), The Surface of Mars. Cambridge Planetary Science Series, Cambridge University Press. It has been considered as a potential site for human exploration due to the presence of icy caves.
