The temple was built on a tell -- an artificial mound formed by millennia of human settlement layered on top of itself. Archaeologists digging beneath the Temple of Bel uncovered a mud-brick structure dating to roughly 2500 BC, followed by Middle Bronze Age and Iron Age structures, all occupying the same sacred ground. A pre-Roman sanctuary, referred to as the Hellenistic temple, preceded the structure that visitors knew. The walls of the temenos and propylaea were constructed in the late first and early second centuries AD. Three Greek builders are known by name from inscriptions, including an architect called Alexandras -- though many Palmyrenes adopted Greco-Roman names, so his ethnicity remains uncertain. The completed temple complex measured approximately 200 by 200 meters, with the cella standing on a podium at the center of the enormous enclosure, its Corinthian columns still bearing pedestals where statues of benefactors once stood.

What made the Temple of Bel remarkable was not just its architecture but its capacity for transformation. When the Praetorian Prefect Maternus Cynegius campaigned against pagan temples across the Eastern Roman Empire between 385 and 388 AD, the temple's religious function ended. Rather than demolishing the structure, Christians repurposed it. Byzantine worshippers gathered where priests had once made offerings to a Mesopotamian triad. When Arab builders arrived in 1132, they preserved the structure again, converting it into a mosque and fortifying the courtyard as a citadel for the village of Tadmur. Mud-brick houses rose among the ruins. The mosque in the temple proper and the surrounding dwellings remained in use until the 1920s, when Franco-Syrian archaeological missions cleared the postclassical elements to expose the Roman-era structure beneath. Each conversion had, paradoxically, protected the building by giving it continued relevance.

On 30 August 2015, ISIS detonated explosives inside the temple's perimeter. Syria's antiquities chief Maamoun Abdulkarim initially reported that the basic structure was still standing. He was wrong. The next day, the United Nations confirmed the destruction after reviewing satellite imagery: "We can confirm destruction of the main building of the Temple of Bel as well as a row of columns in its immediate vicinity." The cella was gone. Bricks and columns lay scattered on the ground. Only one wall and the main entrance arch survived. A resident of Palmyra described columns lying across the courtyard like felled trees. The BBC broadcast satellite imagery narrated by Einar Bjorgo of UN Satellite Imaging, showing the before and after in stark, clinical detail. What five millennia of continuous occupation had preserved, a single act of demolition had largely undone.

The Temple of Bel had been one of Syria's most popular tourist destinations for decades. That popularity proved unexpectedly valuable. Thousands of photographs existed showing the temple from every conceivable angle, making it an ideal candidate for photogrammetric reconstruction -- the creation of 3D models from overlapping images. Researchers at the University of Applied Sciences and Arts Northwestern Switzerland built one such model using tourist images combined with data from photogrammetry pioneer Gabriele Fangi. The New Palmyra Project collected over 3,000 high-resolution photographs and published them as open data on Flickr, preserving the metadata needed for complex image matching. UC San Diego data scientist Scott McAvoy later published a comprehensive reconstruction featuring full-resolution reliefs, frescoes, and decorative details. In the physical world, the French company Art Graphique et Patrimoine traveled to Palmyra in July 2017 to scan the rubble and develop a restoration plan. The temple's entrance arch, which survived the blast, still stands -- a doorway into a room that digital models can show but only reconstruction can restore.