Sungbo Eredo is the largest historical monument in the world... a rampart or system of walls and ditches about 70 feet high and 100 miles round, that surrounds the Yoruba town of Ijebu-Ode in Ogun state.
Sungbo's Eredo has also been connected with the legend of the Queen of Sheba which is recounted in both the Bible and Koran. In the Koran she is an Ethiopian sun worshiper named Bilqis involved in the incense trade who converts to Islam. Local legends link the Eredo to a wealthy childless widow named Bilikisu Sungbo. According to them, the monument was built as her personal memorial.