A wall you can see from space
About an hour's drive from Lagos, in the rainforest of Ogun State, Nigeria, there is a monument so large that generations of archaeologists walked past it without seeing it. Sungbo's Eredo is a system of defensive walls and ditches stretching more than 160 kilometers, in places rising 20 meters from the bottom of the ditch to the top of the bank. It encloses an area some 40 kilometers across. By several measures, it is the largest single monument in Africa.
The earthworks were built around a thousand years ago, in the 800s to 1000s AD. Carbon dating of the ramparts places them in the 10th century, which means a highly organized kingdom existed in this rainforest at least three centuries earlier than historians had believed. The ditch was dug through laterite, the iron-rich African soil, with walls so smooth they look engineered. Trees now flank the banks, turning long stretches of the ditch into a green tunnel.
The woman who built it
Ijebu tradition says the Eredo was built by Oloye Bilikisu Sungbo, a wealthy and powerful noblewoman of the Ijebu kingdom. Local belief goes further: the Ijebu identify Bilikisu Sungbo with the Queen of Sheba herself, the Bilqis of the Quran who visited King Solomon. Her shrine stands at Oke-Eri, near Ijebu-Ode, and remains a sacred site.
Historians note the problem with the identification: the biblical Queen of Sheba is dated to the 10th century BC, two thousand years before the Eredo was built. But the legend points to something real. Whether or not Bilikisu was Sheba, the scale of the monument testifies to a ruler of extraordinary authority, commanding the labor of thousands.
The man who found it again
For all its size, Sungbo's Eredo stayed invisible to science for decades. A first sketch was made in 1959, then nothing happened for nearly forty years. In the 1990s, the British archaeologist Patrick Darling of Bournemouth University stumbled on the ramparts while walking into the undergrowth from the Pan-African Highway, and led the first serious survey. His team mapped the structure with support from Nigeria's National Commission for Museums and Monuments, and their report called it what it is: Africa's largest monument.
Consider the labor. Moving that much earth by hand, through rainforest, a thousand years ago, required an organized state: planners, labor gangs, food supply, and authority that could sustain a project across generations. The Eredo is proof that such a state existed in the Yoruba forest long before European contact.
Still waiting for the world
Sungbo's Eredo sits on Nigeria's tentative list for UNESCO World Heritage status, but it remains little known outside specialist circles and receives few visitors. The monument that may be Africa's greatest single construction project is still, in a sense, hiding in the forest.
A thousand years ago, someone in the Ijebu kingdom ordered a ditch dug around an entire realm, and thousands of people dug it. The walls are still there. The world just hasn't learned to look at them yet.
Sources: Wikipedia: Sungbo's Eredo; Face2Face Africa: The Woman Who Built a Monument Bigger Than the Pyramids
