Ya'juj and Ma'juj
According to Islamic tradition, during the reign of Isa (the Qur'anic name for Jesus), people will live an extremely peaceful life filled with prosperity and abundance. Then the wall which imprisons the nations of Ya'juj and Ma'juj (Gog and Magog in the Bible) will break and they will surge forth in large numbers. There is much debate about the time of release of Ya'juj and Ma'juj. Some Islamic scholars such as the Trinidadian Imran Nazar Hosein believe that the wall containing the Ya'juj and Ma'juj was brought down during the lifetime of the prophet Muhammad. This is supported by evidence from the sayings of Muhammad where he mentions that "a hole has been made in the wall containing the Ya'juj and Ma'juj", indicating the size of the hole with his thumb and index finger.
"But when Ya'jooj and Ma'jooj are let loose and they rush headlong down every hill" (Qur'an 21:96)Read more about this topic: Islamic Eschatology