Over the centuries, Jerusalem’s Church of the Holy Sepulchre has suffered violent attacks, fires, and earthquakes. It was totally destroyed in 1009 and subsequently rebuilt, leading modern scholars to question whether it could possibly be the site identified as the burial place of Christ by a delegation sent from Rome some 17 centuries ago. 
 
 Now the results of scientific tests provided to National Geographic appear to confirm that the remains of a limestone cave enshrined within the church are remnants of the tomb located by the ancient Romans. 
 
 Mortar sampled from between the original limestone surface of the tomb and a marble slab that covers it has been dated to around A.D. 345. According to historical accounts, the tomb was discovered by the Romans and enshrined around 326. 
 
 View Images A restorer removes debris beneath a broken marble slab to expose the original rock surface of what is considered the burial place of Jesus. Photograph by Oded Balilty, AP for National Geographic 
 
 Until now, the earliest architectural evidence found in and around the tomb complex dated to the Crusader period, making it no older than 1,000 years. 
 
 While it is archaeologically impossible to say that the tomb is the burial site of an individual Jew known as Jesus of Nazareth, who according to New Testament accounts was crucified in Jerusalem in 30 or 33, new dating results put the original construction of today's tomb complex securely in the time of Constantine, Rome's first Christian emperor. 
 
 The tomb was opened for the first time in centuries in October 2016, when the shrine that encloses the tomb, known as the Edicule, underwent a significant restoration by an interdisciplinary team from the National Technical University of Athens. 
 
 Several samples of mortar from different locations within the Edicule were taken at that time for dating, and the results were recently provided to National Geographic by Chief Scientific Supervisor Antonia Moropoulou, who directed the Edicule restoration project. 
 
 When Constantine's representatives arrived in Jerusalem around 325 to locate the tomb, they were allegedly pointed to a Roman temple built some 200 years earlier. The Roman temple was razed and excavations beneath it revealed a tomb hewn from a limestone cave. The top of the cave was sheared off to expose the interior of the tomb, and the Edicule was built around it. 
 
 A feature of the tomb is a long shelf, or "burial bed," which according to tradition was where the body of Jesus Christ was laid out following crucifixion. Such shelves and niches, hewn from limestone caves, are a common feature in tombs of wealthy 1st-century Jerusalem Jews. 
 
 The marble cladding that covers the "burial bed" is believed to have been installed in 1555 at the latest, and most likely was present since the mid-1300s, according to pilgrim accounts. 
 
 When the tomb was opened on the night of October 26, 2016, scientists were surprised by what they found beneath the marble cladding: an older, broken marble slab incised with a cross, resting directly atop the original limestone surface of the "burial bed." 
 
 Some researchers speculated that this older slab may have been laid down in the Crusader period, while others offered an earlier date, suggesting that it may have already been in place and broken when the church was destroyed in 1009. No one, however, was ready to claim that this might be the first physical evidence for the earliest Roman shrine on the site. 
 
 Is This Really The Tomb Of Christ? Scholars discuss whether the tomb of Christ is actually the tomb of Christ and how it would have looked. 
 
 The new test results, which reveal the lower slab was most likely mortared in place in the mid-fourth century under the orders of Emperor Constantine, come as a welcome surprise to those who study the history of the sacred monument. 
 
 "Obviously that date is spot-on for whatever Constantine did," says archaeologist Martin Biddle, who published a seminal study on the history of the tomb in 1999. "That's very remarkable." 
 
 During their year-long restoration of the Edicule, the scientists were also able to determine that a significant amount of the burial cave remains enclosed within the walls of the shrine. Mortar samples taken from remains of the southern wall of the cave were dated to 335 and 1570, which provide additional evidence for construction works from the Roman period, as well as a documented 16th-century restoration. Mortar taken from the tomb entrance has been dated to the 11th century and is consistent with the reconstruction of the Edicule following its destruction in 1009. 
 
 "It is interesting how [these] mortars not only provide evidence for the earliest shrine on the site, but also confirm the historical construction sequence of the Edicule," Moropoulou observes. 
 
 The mortar samples were independently dated at two separate labs using optically stimulated luminescence (OSL), a technique that determines when quartz sediment was most recently exposed to light. The scientific results will be published by Moropoulou and her team in a forthcoming issue of the Journal of Archaeological Science: Reports. 
 
 Secrets of Christ’s Tomb premieres Sunday December 3 at 9/8c on the National Geographic Channel. The immersive, 3-D exhibition " Tomb of Christ: The Church of the Holy Sepulchre Experience" is open at the National Geographic Museum in Washington D.C. through the fall of 2018. ||||| View Images The ornate shrine known as the Edicule encloses what is believed to be the tomb of Jesus Christ inside the Church of the Holy Sepulchre in Jerusalem. The shrine has just undergone a year-long restoration. 
 
 Photograph by Oded Balilty, AP for National Geographic 
 
 Scientists have discovered that there is a "very real risk" that the holiest site in Christianity may collapse if nothing is done to shore up its unstable foundations. 
 
 A scientific team from the National Technical University of Athens (NTUA), which has just completed the restoration of what is traditionally believed to be the tomb of Christ in Jerusalem, warns that additional work is needed to prevent the shrine and surrounding complex from experiencing significant structural failure. 
 
 "When it fails, the failure will not be a slow process, but catastrophic," says Antonia Moropoulou, NTUA's chief scientific supervisor. 
 
 View Images During restoration work, scientists discovered that much of the Edicule rests on a foundation of unstable rubble, decayed mortar and tunnels. 
 
 Photograph by Oded Balilty, AP for National Geographic 
 
 The Edicule (from the Latin aedicule, or "little house"), a small structure within the Church of the Holy Sepulchre, encloses the remains of a cave that has been venerated since at least the fourth century A.D. as the tomb of Jesus Christ. 
 
 Restoration of the Edicule reveals that much of the 19th-century shrine and its surrounding rotunda, which host millions of annual visitors, appear to be built largely on an unstable foundation of crumbled remnants of earlier structures and is honeycombed with extensive tunnels and channels. 
 
 EXCLUSIVE: A Closer Look Inside Christ's Unsealed Tomb 
 
 View Images A conservator cleans the surface of the stone slab venerated as the final resting place of Jesus Christ. 
 
 Photograph by Oded Balilty, AP for National Geographic 
 
 While the year-long restoration of the Edicule is being celebrated today in Jerusalem with a ceremony at the church, scientists and church leaders are grappling with the new evidence for significant risks that the engineering work has revealed. 
 
 Layers of History Pose Risk to Future 
 
 The most recent NTUA report provided to National Geographic reveals that much of the risk posed to the tomb is due to the rich history of the venerated site. 
 
 Archaeologists believe that some 2,000 years ago, the site was the location of a defunct limestone quarry that eventually housed tombs of the Jewish upper class. At least half a dozen such tombs have been identified within the grounds of the church, in addition to the tomb traditionally believed to be the burial place of Jesus. 
 
 A Roman temple built on the site in the second century was razed by Constantine, the first Christian emperor of Rome, around 324 A.D. to reveal what was believed to be the tomb of Christ. 
 
 The shrine built by Constantine around the tomb was partly destroyed by Persian invaders in the seventh century A.D. and destroyed again by the Fatimids in 1009. The church was rebuilt in the mid-11th century. The Edicule was later altered by the Crusaders and restored again in the 16th and early 19th centuries. Its current form encloses several earlier construction phases. 
 
 The domed rotunda that surrounds the Edicule is believed to mark the footprint of the original Constantinian church, and possibly the Roman temple that preceded it. 
 
 Tunnels Beneath the Tomb of Christ 
 
 The recent survey beneath the floor of the Edicule and rotunda, conducted during the restoration project, confirmed some of what scientists have long suspected while revealing previously unknown risks to the stability of the entire 3,000-square-foot survey area. 
 
 View Images The rotunda that surrounds the Edicule is believed to mark the footprint of the first church on the site, built around 325 A.D. 
 
 Photograph by Oded Balilty, AP for National Geographic 
 
 Ground-penetrating radar, robotic cameras, and other tools show that some portions of the Edicule's foundation sit on the rubble of earlier buildings. Other parts rest directly on the brink of very steeply sloped, quarried bedrock. Foundation mortar has crumbled due to decades of exposure to moisture from drainage channels that run several feet beneath the rotunda floor. 
 
 Other unexplained tunnels and voids run directly underneath and around the Edicule. An eight-foot-deep archaeological trench dug south of the shrine in the 1960s sits beneath an unsupported concrete slab in an area where visitors have lined up to enter the tomb. 
 
 Several of the 22-ton pillars that hold up the dome of the rotunda rest on more than four feet of unconsolidated rubble. 
 
 The Successful Restoration of the 'Little House' 
 
 The structural integrity of the Edicule has been a concern for nearly a century, but disagreements among the different Christian sects that claim custody of the church, as well as a lack of financial resources, long hindered its repair. 
 
 Following a brief closure of the Edicule by Israeli authorities in 2015 due to safety concerns, the three major Christian groups that maintain primary control over the site—the Greek Orthodox and Armenian Patriarchates of Jerusalem and the Franciscan Custos of the Holy Land—signed an agreement in March 2016 to restore the shrine and the tomb it encloses. 
 
 View Images Christians pray inside the tomb of Jesus at the Church of the Holy Sepulchre. 
 
 Photograph by Oded Balilty, AP for National Geographic 
 
 The Greek NTUA team charged with conserving the Edicule was also responsible for recent restorations of the Acropolis and Hagia Sophia. 
 
 The scientific team worked to reinforce the bowing walls of the Edicule, re-anchoring columns with titanium rods and re-grouting layers of masonry that go back more than a thousand years. 
 
 A ventilation system was installed, in part to alleviate the destructive soot from thousands of candles, and unsightly exterior girders erected by British authorities in 1947 were cut away with a plasma saw. The tomb itself was opened for the first time in centuries. 
 
 The work on the Edicule was successfully completed at a cost of nearly 3.5 million euros. 
 
 No Restoration Without Archaeological Excavation? 
 
 To address the risk of structural collapse at Christianity's holiest site, the NTUA now proposes a 10-month, six-million-euro project that will involve removing the fractured stone paving surrounding the Edicule, grouting foundation rubble and degraded mortar, and excavating more than 1,000 square feet of floor to install new sewage and rainwater drainage around the perimeter of the rotunda. 
 
 The work would be planned in a way to ensure minimal interruption to the approximately four million visitors who come to the tomb each year. 
 
 The possibility that the area below and around the tomb of Christ will be exposed raises new issues about the potential for archaeology at a site that has been the focus of veneration for nearly 2,000 years. 
 
 View Images A Coptic monk dusts the entrance to a chapel on the back of the Edicule. 
 
 Photograph by Oded Balilty, AP for National Geographic 
 
 "This is one of the most complex sites for archaeology at one of the holiest sites in the world," says Martin Biddle, who studied the history of the Edicule for nearly a decade and published a seminal work on the subject in 1999. 
 
 There are "four or five major archaeological stages" under the Edicule, says Biddle, and any exposure of historical levels beneath the modern floor would warrant additional scientific investigation. 
 
 Restoration without archaeological excavation, Biddle says, "would be an intellectual scandal, and I choose my words very carefully." 
 
 The latest report will be shared with the three Christian groups following today's ceremony and a new agreement must be reached before any additional work can go ahead. Meanwhile, the NTUA team is processing the data it has collected and plans to make it available to other scientists on a future "Holy Sephulchre Information Platform." 
 
 "This work is a collective work," says NTUA's chief scientific supervisor Moropoulou. "It doesn’t belong to us, it belongs to all humanity."
– Millions of people flock to Jerusalem's Church of the Holy Sepulchre each year. Many believe it to house the tomb of Jesus Christ, though scientists have thus far been unable to date the tomb to the time when the Romans built a church around it. Now, however, a new series of tests "corroborates our historical accounts" as a National Geographic writer puts it to NBC News. It's easiest to understand the significance by understanding the history: Around AD 325, experts believe Roman Emperor Constantine the Great arrived in Jerusalem on the hunt for places linked to Jesus; his team identified the cave that they believed Jesus was buried in and built a shrine (known as the Edicule) to enclose the tomb and then a church around it. That church was destroyed in 1009, recounts National Geographic. It was rebuilt, and all archaeological dating coincided with that rebuilding—proving it was at most about 1,000 years old. The tomb was opened for the first time in centuries in October 2016 to allow for the Edicule to be restored. A marble slab was discovered beneath marble cladding, and mortar samples taken from the slab dated to around AD 345. National Geographic's take: "While it is archaeologically impossible to say that the tomb is the burial site of an individual Jew known as Jesus of Nazareth ... [the] results put the original construction of today's tomb complex securely in the time of Constantine." (Scientists have issued a dire warning about the site.)