The cart ruts are prehistoric grooves hewn on the rock face, some ten to sixty centimetres deep and fifteen to twenty five centimetres wide. They are generally found in parallel pairs, about one and a half metres apart. No written record was ever found to explain their origin or purpose. Sharp hand tools made out of granite and dating back to pre-history were discovered in the vicinity of the cart ruts. Granite is not a mineral found on the Maltese Islands. Such tools indicate that they were imported, and may have been the tools that the cart ruts were crafted with. No exact dateing can be given, but in some areas Punic tombs have been hewn on top of the cart ruts. Furthermore, at Birzebbuga they proceed below sea level and at Dingli cliffs they stop abruptly on a cliff edge. This may be an indication thaty they must have been created before the Island took its current shape.
Their concentration, overlapping each other like train rails, at this particular site in Buskett, led to believe that this must have been a very busy communication network. It was nicknamed Clapham Junction after a busy railway station in Britain.