Axum Empire

One of the churches in ancient Aksum, Church of Our Lady Mary of Zion, is said to have the Ark of the Covenant in its possession. However, the shrine is guarded by a single guardian (a monk) and no one is allowed inside, not even the rulers of Ethiopia or the heads of the Ethiopian church.

An excerpt from the article 20 facts about Axum Empire
Church of Our Lady Mary of Zion was built in the 17th century on a previously destroyed one that probably dates back to the 4th century. Next to the church is the so-called Chapel of the Tablets. It was built in 1964 during the reign of Emperor Haile Syllasje I. Previously, the Ark of the Covenant was kept in the old church, now housed in the Chapel of the Tablets.