During the Middle Ages, Africans built the largest city of the medieval world. It is located approximately 90 kilometres from Lagos. The city was bigger than Baghdad, Cairo, Cordoba and Rome, and it traded in gold and ivory. What remains of this city is a huge earthen wall, with moated sections that encircled it, called “Sungbo’s Eredo”. The total length of the wall is approximately 160 kilometres. The height difference between the bottom of the ditch and the upper rim of the bank on the inner side can reach 20 metres. The diameter of this enormous fortification in a north-south direction is approximately 40 km and in an east-west direction, 35 kilometres.
A three-storey ruin was also discovered, which has been identified as the royal palace. It had living quarters, shrines and courtyards.
The Eredo Wall is believed to have been built over a thousand years ago between, 800 AD and 1000 AD, a period of political confrontation and consolodation in the South Nigeria rainforest, by Queen Bilikisu Sungbo. She built this wall to protect the city against invasions. Her actual grave is located in Oke Eri Village in Ijebu area of Ogun State, Nigeria. Pilgrims of Christian, Muslim and African religions annually trek to her grave in tribute to her. Some go there to offer prayers for personal issues. Some go back there to thank the mysterious Queen for answered prayers.