The Catholic, Armenian and Orthodox churches have all agreed to contribute money towards the renovation of the Aedicule (entrance above) - a site marking where it's thought Jesus was buried before His resurrection.
It's the inside the Church of the Holy Sepulchre in Jerusalem, which also marks the site considered to be where Jesus was crucified.
The restoration work is being carried by experts at the National Technological University of Athens, with Antonia Moropoulou leading the effort.
The current Aedicule shrine was built more than 200 years ago in 1810, however, the mortar holding the marble slabs together is beginning to wear.
Christians from the three churches have physically assaulted each other publicly in the Church of the Holy Sepulchre and have also been known to sing over each other's prayers, leading to reports that the three denonimations do not get along - particularly within one of the most famous Christian sites in the world.
The joint move to restore the Aedicule within the church will be viewed as not only an attempt to maintain a pivotal Christian heritage site, but also as an effort to build relations between the three churches.
The Jerusalem Patriarchate said on its website: "The Heads of the three Major Communities, namely the Orthodox, Franciscans [Catholics] and Armenians, thanked Ms Moropoulou for delivering a thorough report and agreed to sign an agreement for the promotion and execution of this historical project for the praise of Christians and the glory of the Triadic God.
It also posted a video of the three churches reaching the landmark deal, along with a report on the upcoming restoration work:
